Debug event handling

ABSTRACT

Systems and methods are disclosed for debug event handling. For example, methods may include receiving a request from a client device. Methods may include, responsive to receiving the request, identifying a set of instructions to be executed, wherein the set of instructions is associated with at least one breakpoint. Methods may include initiating execution of the set of instructions. Methods may include pausing execution of the set of instructions when an instruction of the set of instructions associated with a breakpoint is reached. Methods may include, after the breakpoint is reached and before a new request is received from the client device, transmitting, to the client device, a message that indicates that a breakpoint has been reached. Methods may include terminating execution of the set of instructions responsive to determining that a debugger interface on the client device is no longer available to control execution of the set of instructions.

TECHNICAL FIELD

This disclosure relates in general to debug event handling.

BACKGROUND

This section is intended to introduce the reader to various aspects ofart that may be related to various aspects of the present disclosure,which are described and/or claimed below. This discussion is believed tobe helpful in providing the reader with background information tofacilitate a better understanding of the various aspects of the presentdisclosure. Accordingly, it should be understood that these statementsare to be read in this light, and not as admissions of prior art.

Software code, such as scripts may include errors, which can also bereferred to as bugs. Persons responsible for writing or maintaining codeneed to find bugs in their code and fix them. Running code up to astopping point and examining the values of variables used by the codecan help to find bugs in the code so that those bugs may be fixed.Debuggers are tools used by developers of code to help them find bugs intheir code. Debuggers, can for example, run code being debugged until aninstruction associated with a breakpoint is reached and then pauseexecution. Which instructions in the code are associated withbreakpoints may be selected by a user. The input passed to an instanceof code being debugged may affect which instructions in the code areactually executed.

A server can provide a server-based web application (e.g., usingplatform software to provide configurable and extensible functionalityfor developing web-based applications). A client and a server cancommunicate over protocols such as HTTP. Client-server interactions canbe carried out over a series of related client requests and serverresponses. A computing network environment may impose restrictions onthe types of messages that can sent from a server to a client. Forexample, some computer networks use firewalls that may prevent a serverfrom sending unsolicited messages to a client.

An application can maintain state between requests by using a datastructure (e.g., a session data structure) to store state informationused by the application. For example, a session can start with the firstrequest that the client makes to the server and can end when the clientdisconnects or the session times out and a corresponding session datastructure may be maintained during that period of time. The stateinformation stored in a data structure can be application-specific andinclude information relating to components, contexts, user interfaceelements, data, and other parameters related to a current state of aclient-server interaction.

BRIEF DESCRIPTION OF THE DRAWINGS

The description herein makes reference to the accompanying drawings,wherein like reference numerals refer to like parts throughout theseveral views.

FIG. 1 is a block diagram of an example of an electronic computing andcommunications system.

FIG. 2 is a block diagram of an example internal configuration of acomputing device of an electronic computing and communications system.

FIG. 3 is a diagram of example communications to facilitate debugging,from a client device, of a set of instructions running on a serverdevice in an example electronic computing and communications system.

FIG. 4 is a flowchart illustrating an example of a technique forexecuting a set of instructions to be debugged via a session with aclient device.

FIG. 5 is a flowchart illustrating an example of a technique fortransmitting, to a client device, an indication that a breakpoint wasreached when execution pauses at a breakpoint.

FIG. 6 is a flowchart illustrating an example of a technique forterminating or modifying the execution of a set of instructions runningin a debug mode responsive to determining that a debugger interface on aclient device has become unavailable to control execution of the set ofinstructions.

FIG. 7 is a flowchart illustrating an example of a technique forcontrolling access to sections of a set of instructions associated withbreakpoints while running a debugger.

FIG. 8 is a flowchart illustrating an example of a technique forcontrolling access to instructions in functions while running adebugger.

FIG. 9 is a diagram of an example display region generated forpresenting a debugger interface.

FIG. 10 is a diagram of an example display region generated forpresenting debug transaction details to facilitate debugging, from aclient device, of a set of instructions running on a server.

FIG. 11A is a memory map showing an example format for a session datastructure that is used to facilitate debugging, from a client device, ofa set of instructions running on a server.

FIG. 11B is a memory map showing an example format for a data structureassociated with a session that is used to facilitate debugging, from aclient device, of a set of instructions running on a server.

FIG. 12 is a state diagram of an example interface for debugging, from aclient device, of a set of instructions running on a server.

FIG. 13 is a state diagram of an example session access controller fordebugging, from a client device, of a set of instructions running on aserver.

FIG. 14 is a state diagram of an example session access controller fordebugging, from a client device, of a set of instructions running on aserver.

DETAILED DESCRIPTION

In computing and communications networks, services may be provided by aset of instructions (e.g., code) running on servers (e.g., web servers,database servers, file servers, mail servers, or application servers).Some users, working on client devices, may write or modify a set ofinstructions that runs on a server to provide services. For example,customers of a platform-as-a-service (PaaS) cloud computing provider cancustomize platform software to deliver application software based ontheir particular service and business management needs. For example, acustomer can customize the platform software by adding or modifyingscripts for executing routines related to services deliverable by thecustomer, but which are not native to the platform software. AllowingPaaS customers to develop software implementing their customization ofplatform software from a client device can present challenges. Whenhumans write or modify a set of instructions, bugs (i.e., coding errors)may occur. Users often need to find bugs in a set of instructionswritten by themselves or others. A debugger interface that allows a userto pause execution of the set of instructions and examine the state ofvariables may help the user to efficiently find bugs and fix the set ofinstructions.

Debugging a set of instructions that is running on a remote device maypresent challenges. For example, remote debugging via networkcommunications may be subject to unplanned disconnections and/orsignificant latency introduced by a network communications environment(e.g., caused by limitations imposed by a network firewall). Forexample, there may be challenges with regard to sharing computingresources, among many users and/or threads, on a server running a set ofinstructions being debugged, which may run slow and be subject tofrequent paused states.

In some implementations (e.g., some of the implementations described inrelation to FIG. 4), resource sharing among threads, including threadsrunning a set of instructions with a debugger, is facilitated byincluding a pause marker (e.g., a semaphore or a mutex) for a sessiondata structure storing state information for communications with aclient device controlling one or more debugger instances running on aserver. For example, a pause marker may be used by the server to preventa case where two debugger instances from the same user are pausedconcurrently and/or to facilitate resuming execution of a set ofinstructions being debugged from a pause based on a user command issuedvia another transaction in the session.

For example, using a pause marker may enable a thread-safe controlchannel for managing the state of the debugged transaction using debugcontrol transactions that can run normally while execution of a set ofinstructions for a debugged transaction is paused. The pausedtransaction is able to safely release its lock on a session datastructure while it is paused, allowing other transactions, includingdebug control transactions, to be executed using the session datastructure. This configuration may allow use of standard PaaS serverbehaviors (especially access control, which may include scripts) withindebug control channel transactions.

In some implementations (e.g., some of the implementations described inrelation to FIGS. 4-6), event-based messaging is used to reduce latencyexperienced when using a debugger instance controlled from a clientdevice. For example, when a set of instructions that is being executedin a debug mode reaches a breakpoint, execution of the set ofinstructions may be paused, and a message indicating that the breakpointwas reached may be sent to the client device without waiting for theclient device to send a subsequent request for that information. In thismanner, delays associated with waiting for a client request to be issuedafter a debugger instance pauses on the server may be avoided. In someimplementations, a server running a debugger instance may determine whena client device that requested the debugger instance to run has becomedisconnected from the server and may terminate the debugger instance orallow the set of instructions being debugged to finish running in anon-debug mode (e.g., a production mode) where it skips remainingbreakpoints. In this manner, limited computing resources on a server maybe conserved in the presence of debugging instances running in responseto network communications from client devices.

In some implementations (e.g., some of the implementations described inrelation to FIG. 3), user debugging, from a client device, of a set ofinstructions (e.g., a script) running on a server may be facilitated bycommunications between a debugger instance running on the server and adebugger interface running on the client device. For example, a debuggerinstance running on the server may identify a set of instructions to bedebugged based on a request from the client device and execute theidentified set of instructions, enabling execution to be paused atbreakpoints associated with instructions of the identified set ofinstructions and the values of variables used by the identified set ofinstructions to be determined. For example, a debugger interface runningon a client device may provide user interface (e.g., including thedisplay region 910 of FIG. 9) to the user and enable the user to control(e.g., by setting breakpoints and/or issuing step commands) execution ofthe identified set of instructions and to examine the state (e.g.,including the values of variables used by the identified set ofinstructions) when execution on the server is paused. For example,commands to control execution of the identified set of instructions maybe passed from the debugger interface on the client device to thedebugger instance on the server in requests transmitted via networkcommunications. For example, state information about the identified setof instructions being debugged may be passed from the debugger instanceon the server to the debugger interface on the client device via networkcommunications.

In some implementations, a set of instructions identified for debuggingmay include, for example, interpretable text (e.g., JavaScript),compiled code (e.g., compiled Java or C code), bytecode, and/or othercomputer-executable instructions. In some implementations, aninstruction of a set of instructions may be executed by interpreting(e.g., using a JavaScript interpreter) that the instruction.

Implementations of this disclosure provide technological improvementsparticular to computer networks, for example, those concerning remotelyprogrammable web applications. Computer network-specific technologicalproblems, such as managing a session state to facilitate debugging of aset of instructions running on a server from a client device, can bewholly or partially solved by implementations of this disclosure. Forexample, the state of a session including transactions for one or moredebugger instances may be managed in a thread-safe manner. Theimplementations of this disclosure introduce new and efficientimprovements in the ways in which a state for a debugger stored in aclient device may be synchronized with a state of the debugger runningthe set of instructions to be debugged on a server by using alow-latency, event-based messaging system.

To describe some implementations in greater detail, reference is firstmade to examples of hardware structures. FIG. 1 is a block diagram of anexample of an electronic computing and communications system 100. Asused herein, the term “electronic computing and communications system,”or variations thereof, can be, or include, a distributed computingsystem (e.g., a client-server computing system), a cloud computingsystem, a clustered computing system, or the like.

The system 100 can include one or more customers 102. The customer 102can include one or more clients. For example, and without limitation,the customer 102 can include a client 104. The client 104 can comprise acomputing system, which can include one or more computing devices, suchas a mobile phone, a tablet computer, a laptop computer, a notebookcomputer, a desktop computer, or any other suitable computing device orcombination of computing devices. In some implementations, the client104 can be implemented as a single physical unit or as a combination ofphysical units. In some implementations, a single physical unit caninclude multiple clients.

The client 104 can be an instance of an application running on acustomer device associated with the customer 102. As used herein, theterm “software” can include, but is not limited to, applications,programs, instances, processes, threads, services, plugins, patches,application version upgrades, or any other identifiable computing unitcapable of accessing or interacting with, directly or indirectly, adatabase. The system 100 can include any number of customers or clientsor can have a configuration of customers or clients different from thatgenerally illustrated in FIG. 1. For example, and without limitation,the system 100 can include hundreds or thousands of customers, and atleast some of the customers can include or be associated with any numberof clients. A customer can include a customer network or domain. Forexample, and without limitation, the client 104 can be associated orcommunicate with a customer network or domain.

The system 100 can include a datacenter 108. The datacenter 108 caninclude one or more servers. For example, and without limitation, thedatacenter 108, as generally illustrated, includes an application server112 and a database server 116. A datacenter, such as the datacenter 108,can represent a geographic location, which can include a facility, wherethe one or more servers are located. The system 100 can include anynumber of datacenters and servers or can include a configuration ofdatacenters and servers different from that generally illustrated inFIG. 1. For example, and without limitation, the system 100 can includetens of datacenters, and at least some of the datacenters can includehundreds or any suitable number of servers. In some implementations, thedatacenter 108 can be associated or communicate with one or moredatacenter networks or domains, which can include domains other than theclient domain.

The client 104 and the servers associated with the datacenter 108 may beconfigured to connect to, or communicate via, a network 106.Furthermore, a client 104 associated with the customer 102 can connectto the network 106 via a communal connection point, link, or path orusing a distinct connection point, link, or path. A connection point,link, or path can be wired, wireless, use other communicationstechnologies, or a combination thereof.

The network 106 can include, for example, the Internet, and/or thenetwork 106 can be, or include, a local area network (LAN), a wide areanetwork (WAN), a virtual private network (VPN), or any other public orprivate means of electronic computer communication capable oftransferring data between a client, such as the client 104, and one ormore servers associated with the datacenter 108, or a combinationthereof. The network 106, the datacenter 108, or any other element, orcombination of elements, of the system 100 can include network hardwaresuch as routers, switches, load balancers, other network devices, orcombinations thereof. For example, the datacenter 108 can include a loadbalancer 110 for routing traffic from the network 106 to various serversassociated with the datacenter 108.

The load balancer 110 can route, or direct, computing communicationtraffic, such as signals or messages, to respective elements of thedatacenter 108. For example, the load balancer 110 can operate as aproxy, or reverse proxy, for a service, such as an Internet-deliveredservice, provided by the datacenter 108 to one or more remote clients,such as the client 104, via the network 106. Routing functions of theload balancer 110 can be configured directly or via a Domain Name System(DNS). The load balancer 110 can coordinate requests from remoteclients, such as the client 104, and can simplify client access bymasking the internal configuration of the datacenter 108 from the remoteclients. Request coordination can include maintaining information forsessions, such as sticky sessions, between a client and a service orapplication provided by the datacenter 108.

Maintaining information for a sticky session can include maintaininginformation to forward requests associated with a session from a clientto an identified element of the datacenter 108 for the session. A loadbalancer 110 can operate as a firewall, allowing or preventingcommunications based on configuration settings. Although the loadbalancer 110 is depicted in FIG. 1 as being within the datacenter 108,in some implementations, the load balancer 110 can instead be locatedoutside of the datacenter 108, for example, when providing globalrouting for multiple datacenters. In some implementations, loadbalancers can be included both within and outside of the datacenter 108.

The datacenter 108 may include an application server 112 and a databaseserver 116. The application server 112 or the database server 116 can bea computing system, which can include one or more computing devices,such as a desktop computer, a server computer, or any other computercapable of operating as a server. In some implementations, theapplication server 112 or the database server 116 can be non-hardwareservers implemented on a physical device, such as a hardware server. Insome implementations, the application server 112 and the database server116 can be implemented as a single hardware server or as a singlenon-hardware server implemented on a single hardware server. Of course,any number of application servers or database servers can be implementedat the datacenter 108 and the datacenter 108 can include servers otherthan or in addition to the application server 112 or the database server116, for example, a web server.

In some implementations, the application server 112 includes anapplication node 114, which can be a process executed on the applicationserver 112. For example, and without limitation, the application node114 can be executed in order to deliver services to a client, such asthe client 104, as part of a web application. The application node 114can be implemented using processing threads, virtual machineinstantiations, or other computing features of the application server112. In some implementations, the application node 114 can store,evaluate, or retrieve data from a database, such as the database 118 ofthe database server 116.

The application server 112 can include any suitable number ofapplication nodes, depending upon a system load or other characteristicsassociated with the application server 112. For example, and withoutlimitation, the application server 112 can include two or more nodesforming a node cluster. The application nodes implemented on a singleapplication server 112 may run on different hardware servers.

The database server 116 can be configured to store, manage, or otherwiseprovide data for delivering services to the client 104 over a network.The database server 116 may include a data storage unit, such as adatabase 118, which can be accessible by an application executed on theapplication node 114. The database 118 may be implemented as arelational database management system (RDBMS), an object database, anXML database, a configuration management database (CMDB), a managementinformation base (MIB), one or more flat files, other suitablenon-transient storage mechanisms, or a combination thereof. By way ofnon-limiting example, the system 100, in some implementations, caninclude an XML database and a CMDB. While limited examples aredescribed, the database 118 can be configured as or comprise anysuitable database type. Further, the system 100 can include one, two,three, or any suitable number of databases configured as or comprisingany suitable database type or combination thereof.

In some implementations, the database 118 can be configured as orcomprise a CMDB. A CMDB can be comprised of a plurality of configurationitems (CIs), attributes associated with the CIs, or relationshipsbetween the CIs. A CI can be a CMDB record that represents aninfrastructure entity, device, or units of the system 100. For example,the customer 102, the client 104, the network 106, the datacenter 108,the load balancer 110, the application server 112, the application node114, the database server 116, the database 118, or any other element,portion of an element, or combination of elements of the electroniccomputing and communications system 100 can be represented in the CMDBby a CI.

The CMDB can include information describing the configuration, the role,or both the configuration and the role, of an element of the system 100.In some implementations, an MIB can include one or more databaseslisting characteristics of the elements of the system 100. In someimplementations, an object identifier (OID) can represent objectidentifiers of objects or elements in the MIB.

In some implementations, one or more databases (e.g., the database 118),tables, other suitable information sources, or portions or combinationsthereof can be stored, managed, or otherwise provided by one or more ofthe elements of the system 100 other than the database server 116, suchas the client 104 or the application server 112.

Some or all of the systems and methods described herein can operate orbe executed on or by the servers associated with the system 100. Forexample, an update for an application executed on the application node114 can include updating or upgrading the database 118. In someimplementations, the systems and methods described herein, portionsthereof, or combinations thereof can be implemented on a single device,such as a single server, or a combination of devices, for example, acombination of the client 104, the application server 112, and thedatabase server 116.

In some implementations, the system 100 can include devices other thanthe client 104, the load balancer 110, the application server 112, andthe database server 116 as generally illustrated in FIG. 1. In someimplementations, one or more additional servers can operate as anelectronic computing and communications system infrastructure control,from which servers, clients, or both servers and clients, can bemonitored, controlled, configured, or a combination thereof.

The network 106, one or more datacenters, such as the datacenter 108,and one or more load balancers, such as the load balancer 110, may beimplemented within a distributed computing system. A load balancerassociated with a distributed computing system (e.g., the load balancer110) can communicate with the network 106, one or more datacenters(e.g., the datacenter 108), other load balancers, or a combinationthereof. The load balancer 110 can be configured to route communicationsto a primary datacenter, identify a failover condition (e.g., such as anenumerated failover condition) at the primary datacenter, and redirectcommunications to a secondary datacenter until the failover condition isresolved. Although illustrated as a single unit in FIG. 1, a loadbalancer 110 can be implemented as multiple physical or logical units.For example, a distributed computing system can include distinct routingunits, load balancing units, firewall units, or the like.

The primary datacenter can include a primary database, such as thedatabase 118, and the secondary datacenter can include a secondarydatabase. The secondary database can include an exact or substantiallyexact mirror, copy, or replication of the primary database. The primarydatabase or the secondary database can be implemented as a relationaldatabase management system (RDBMS), an object database, an XML database,one or more flat files, or the like.

An application node implemented within a distributed computingenvironment can connect to or communicate with the primary database,which can be associated with the datacenter with which the applicationnode is associated, or associated with another datacenter. For example,a primary datacenter can include a primary database and a first set ofapplication nodes. A secondary datacenter can include a secondarydatabase and a second set of application nodes. The application nodes ofthe first and second sets can provide a service or application to remoteclients, and can read or write data in the primary database. Thesecondary database can mirror changes made to the primary database andprevent write operations from being performed directly on the secondarydatabase. In the event that a failover condition associated with theprimary database is identified, the secondary database can operate asthe primary database and can allow read or write access to data. Theprimary database can then operate as the secondary database, mirror thenew primary database, and prevent direct write access to the newsecondary database.

A distributed computing system can allocate resources of a computernetwork using a multi-tenant or single-tenant architecture, for example.Allocating resources in a multi-tenant architecture can includeinstallations or instantiations of one or more servers, such asapplication servers, database servers, or any other server, orcombination of servers, that can be shared amongst multiple customers.For example, a web server, such as a unitary Apache installation; anapplication server, such as a unitary Java Virtual Machine; or a singledatabase server catalog, such as a unitary MySQL catalog, can handlerequests from multiple customers. In some implementations of amulti-tenant architecture, the application server, the database server,or both can distinguish between and segregate data or other informationof the various customers using the system.

In a single-tenant infrastructure (which can also be referred to as amulti-instance architecture), separate web servers, application servers,database servers, or combinations thereof can be provisioned for atleast some customers or customer sub-units. Customers or customersub-units can access one or more dedicated web servers, havetransactions processed using one or more dedicated application servers,or have data stored in one or more dedicated database servers, catalogs,or both. Physical hardware servers can be shared such that multipleinstallations or instantiations of web servers, application servers,database servers, or combinations thereof can be installed on the samephysical server. An installation can be allocated a portion of thephysical server resources, such as RAM, storage, communicationsbandwidth, or processor cycles.

Platform software may be implemented by a PaaS service provider usingexecutable instructions. The PaaS service provider can execute distinctinstances of the platform software for respective customers, such that acustomer can access its instance of the platform software bycommunicating with a server device executing the instance. In someimplementations, an instance of platform software can be implementedusing one or more application nodes and one or more database nodes, suchas the application node 114 and database 118 shown in FIG. 1, whereinthe application node 114 can implement a version of the platformsoftware and the database 118 can store a version of platform data usedby the version of the platform software and a version of user datacreated by a user of the instance. A customer may be enabled tocustomize the platform software by developing code (e.g., scripts) thatare integrated with the platform software. For example, a customer maybe provided with an interface for debugging scripts running on a PaaSservice provider server (e.g., the application server 112) from a clientdevice (e.g., the client 104).

A customer instance can include multiple web server instances, multipleapplication server instances, multiple database server instances, or acombination thereof. The server instances can be physically located ondifferent physical servers and can share resources of the differentphysical servers with other server instances associated with othercustomer instances. In a distributed computing system, multiple customerinstances can be used concurrently. Other configurations orimplementations of customer instances can also be used. The use ofcustomer instances in a single-tenant architecture can provide, forexample, true data isolation from other customer instances, advancedhigh availability to permit continued access to customer instances inthe event of a failure, flexible upgrade schedules, an increased abilityto customize the customer instance, or a combination thereof.

FIG. 2 is a block diagram of an example of an internal configuration ofa computing device 200 of an electronic computing and communicationssystem, such as a client 104 or a server, such as an application server112 or a database server 116, of the system 100 shown in FIG. 1. Aspreviously described, a client or server can be a computing systemincluding multiple computing devices or a single computing device, suchas a mobile phone, a tablet computer, a laptop computer, a notebookcomputer, a desktop computer, a server computer, or other suitablecomputing devices. A computing device 200 can include components orunits, such as a processor 202, a bus 204, a memory 206, peripherals214, a power source 216, a network communication unit 218, a userinterface 220, other suitable components, or a combination thereof.

The processor 202 can be a central processing unit (CPU), such as amicroprocessor, and can include single or multiple processors havingsingle or multiple processing cores. Alternatively, the processor 202can include another type of device, or multiple devices, now existing orhereafter developed, capable of manipulating or processing information.For example, the processor 202 can include multiple processorsinterconnected in any manner, including hardwired or networked,including wirelessly networked. In some implementations, the operationsof the processor 202 can be distributed across multiple physical devicesor units that can be coupled directly or across a local area or othersuitable type of network. In some implementations, the processor 202 caninclude a cache, or cache memory, for local storage of operating data orinstructions.

The memory 206 can include volatile memory, non-volatile memory, or acombination thereof. For example, the memory 206 can include volatilememory, such as one or more DRAM modules such as DDR SDRAM, andnon-volatile memory, such as a disk drive, a solid state drive, flashmemory, Phase-Change Memory (PCM), or any form of non-volatile memorycapable of persistent electronic information storage, such as in theabsence of an active power supply. The memory 206 can include anothertype of device, or multiple devices, now existing or hereafterdeveloped, capable of storing data or instructions for processing by theprocessor 202. The processor 202 can access or manipulate data in thememory 206 via the bus 204. Although shown as a single block in FIG. 2,the memory 206 can be implemented as multiple units. For example, acomputing device 200 can include volatile memory, such as RAM, andpersistent memory, such as a hard drive or other storage.

The memory 206 can include executable instructions 208, data, such asapplication data 210, an operating system 212, or a combination thereof,for immediate access by the processor 202. The executable instructions208 can include, for example, one or more application programs, whichcan be loaded or copied, in whole or in part, from non-volatile memoryto volatile memory to be executed by the processor 202. The executableinstructions 208 can be organized into programmable modules oralgorithms, functional programs, codes, code segments, or combinationsthereof to perform various functions described herein. For example, theexecutable instructions 208 can include machine-readable code to executea set of instructions in a debug mode with access to data for a sessionwith a client device, transmit an indication to a client device that abreakpoint was reached when the set of instructions running in the debugmode is paused, or terminate or modify execution of the set ofinstructions running in the debug mode upon disconnection from a clientdevice. The application data 210 can include, for example, user files,database catalogs or dictionaries, configuration information orfunctional programs, such as a web browser, a web server, a databaseserver, or a combination thereof. The operating system 212 can be, forexample, Microsoft Windows®, Mac OS X®, or Linux®, an operating systemfor a small device, such as a smartphone or tablet device; or anoperating system for a large device, such as a mainframe computer. Thememory 206 can comprise one or more devices and can utilize one or moretypes of storage, such as solid state or magnetic storage.

The peripherals 214 can be coupled to the processor 202 via the bus 204.The peripherals 214 can be sensors or detectors, or devices containingany number of sensors or detectors, which can monitor the computingdevice 200 itself or the environment around the computing device 200.For example, a computing device 200 can contain a geospatial locationidentification unit, such as a global positioning system (GPS) locationunit. As another example, a computing device 200 can contain atemperature sensor for measuring temperatures of components of thecomputing device 200, such as the processor 202. Other sensors ordetectors can be used with the computing device 200, as can becontemplated. In some implementations, the power source 216 can be abattery, and the computing device 200 can operate independently of anexternal power distribution system. Any of the components of thecomputing device 200, such as the peripherals 214 or the power source216, can communicate with the processor 202 via the bus 204.

The network communication unit 218 can also be coupled to the processor202 via the bus 204. In some implementations, the network communicationunit 218 can comprise one or more transceivers. The networkcommunication unit 218 can, for example, provide a connection or link toa network, such as the network 106, via a network interface, which canbe a wired network interface, such as Ethernet, or a wireless networkinterface. For example, the computing device 200 can communicate withother devices via the network communication unit 218 and the networkinterface using one or more network protocols, such as Ethernet, TCP,IP, power line communication (PLC), WiFi, infrared, GPRS, GSM, CDMA, orother suitable protocols.

A user interface 220 can include a display; a positional input device,such as a mouse, touchpad, touchscreen, or the like; a keyboard; orother suitable human or machine interface devices. The user interface220 can be coupled to the processor 202 via the bus 204. Other interfacedevices that permit a user to program or otherwise use the computingdevice 200 can be provided in addition to or as an alternative to adisplay. In some implementations, the user interface 220 can include adisplay, which can be a liquid crystal display (LCD), a cathode-ray tube(CRT), a light emitting diode (LED) display (e.g., an OLED display), orother suitable display.

In some implementations, a client or server can omit the peripherals214. The operations of the processor 202 can be distributed acrossmultiple clients or servers, which can be coupled directly or across alocal area or other suitable type of network. The memory 206 can bedistributed across multiple clients or servers, such as network-basedmemory or memory in multiple clients or servers performing theoperations of clients or servers. Although depicted here as a singlebus, the bus 204 can be composed of multiple buses, which can beconnected to one another through various bridges, controllers, oradapters.

FIG. 3 is a diagram of example communications to facilitate debugging,from a client device, of a set of instructions (e.g., code) running on aserver device in an example electronic computing and communicationssystem 300. The system 300 may include a server device 302 that maycommunicate via a network 306 with client devices 310, 312, and 314. Theclient devices 310, 312, and 314 may include a user interface (e.g., theweb browsers 320, 322, and 324) that facilitates communication withserver devices, such as the server device 302. The server device 302 mayinclude an application module 330 that provides services to users ofclient devices (e.g., the client device 312), including a capability torun a set of instructions (e.g., code) in a debug mode on the serverdevice 302 and access a debugger interface on a client device (e.g.,through the web browser 322).

For example, the client device 312 may be the client 104 as described inrelation to FIG. 1. The web browser may be, for example, Chrome®,Firefox®, Safari®, or Internet Explorer®. For example, the network 306may be the network 106 as described in relation to FIG. 1. For example,the server device 302 may be the application server 112 of FIG. 1. Insome implementations, the application module 330 may be the applicationnode 114 of FIG. 1. For example, the application module 330 may includea java virtual machine (JVM) running compiled java code to provideservices to clients.

The application module 330 may pass scripts to a script module 340 forexecution. For example, the script module may be a JavaScript engine(e.g., Rhino®). The script module 340 may include an interpreter 342 forinterpreting lines of code from a script as part of executing thescript. The script module 340 may include a debug controller 344 thatenables line-by-line control of the execution of a script. For example,the application module 330 may control execution of a script on aline-by-line basis by using a debug API (application programminginterface) provided by the debug controller 344. As a next line of thescript for execution is processed, the application module 330 mayreceive a callback to a callback function that it previously registeredwith the script module 340 through the API provided by the debugcontroller 344. In some implementations, this callback function is acode (e.g., a compiled Java code running on a JVM) that implementsdebugger logic to enable a user at a client device (e.g., the clientdevice 312) to debug a set of instructions (e.g., code) being executedon the server device 302.

The callback function implemented by the application module 330 mayexamine information about a script and/or a related debugger instance(e.g., the session data 350 and/or the markers 352) to determine ifthere is a breakpoint associated with the next instruction (e.g., a lineof code) and whether, under the current circumstances, the execution ofthe script should be paused at the breakpoint. If an applicablebreakpoint is detected, but it is determined that the breakpoint shouldbe skipped, the callback function may issue a command through the debugAPI to execute this next line of the script. If an applicable breakpointis detected and it is determined that execution should be paused at thebreakpoint, the callback function may issue a command through the debugAPI to pause execution at this next line of the script or withhold (forthe time being) a command to execute this next line of the script. Insome implementations, the application module 330 may use this callbackfunction to determine that a breakpoint will be skipped if, for example,a limit on the number of concurrent debug instances using resources(e.g., a session data structure or a processor) would be exceeded or auser of a debug instance lacks permission to access the instruction(e.g., a line of code) associated with the breakpoint.

In an example scenario, a user of the client device 312 may use abrowser to open a session with the application module 330 running on theserver device 302. One or more requests 360 may then be transmitted fromthe client device 312 to the server device 302 to initiate and controlthe debugging of a script that will run on the server device 302. Forexample, a user may issue a command (e.g., by clicking a debugger iconor selecting a menu option) in the web browser 322 to indicate that adebugger should be started, which may cause a request 360 to betransmitted to the server device 302. When the request is received bythe server device 302, the application module 330 may identify a set ofinstructions (e.g., a server-side script) that will be executed in adebug mode in response to the request. The application module 330 mayinitiate execution of the set of instructions, for example, by passingan identified script to the script module 340 and using a debug APIprovided by the debug controller 344 to control the execution of thescript on a line-by-line basis. Execution of the script may continueuntil the application module 330 determines that a line or instructionof a script corresponding to a first breakpoint has been reached.

The application module 330 may check to determine if conditions requiredfor pausing on the breakpoint are satisfied. For example, theapplication module 330 may determine whether too many threads would beconcurrently paused using the session data 350 associated with therequest 360, by checking a pause marker 352 (e.g., a semaphore)associated with the session data 350. For example, the applicationmodule 330 may determine whether a user associated with the request haspermission to access the instruction associated with the breakpoint(e.g., read permission for the script file in which the instructionoccurs). Where the conditions are satisfied, the application module 330may cause execution of the script to be paused (e.g., using the debuggerAPI of the script module 340). In some implementations, the applicationmodule 330 may then transmit a message 370 to the client device 312 thatindicates that a breakpoint has been reached, without waiting for a newrequest from the client device, so that the new state of the pausedscript may be promptly synchronized (e.g., as part of the session data350) with its corresponding representation on the client device fordisplay to a user (e.g., in the web browser 322).

The markers 352 may be stored separately from the session data they areassociated with (e.g., they may be stored in a table of markers forregistered sessions active on the server device 302). In someimplementations, the markers 352 may be stored as a part of the sessiondata to which they pertain (e.g., a marker may include one or morefields stored in a session data record). The session data 350 and/or themarkers 352 may be stored in memory on the server device 302 (e.g., inthe memory 206). In some implementations (not shown in FIG. 3), thesession data 350 and/or the markers 352 are stored in memory on anotherdevice (e.g., the database server 116) and accessed by the applicationmodule 330 from the server device 302 via network communications.

Subsequent requests 360 may be transmitted from the client device 312 tothe server device 302 to continue the debugging of the script. Forexample, the requests 360 may be sent to step into, step over the nextline of the script, or resume execution of the script until the nextbreakpoint is reached. For example, a step operation may be implementedby generating a temporary breakpoint associated with an instructionimmediately after the next instruction in the script, so that theexecution will pause again after executing the next instruction.Messages updating the client device 312 about changes in the status ofthe debugger may be transmitted by the server device 302 as the newinformation becomes available. If at some point the client device 312becomes disconnected from the server device 302 (e.g., due to a crash ofthe client device or a network service disruption), the server device302 may determine that a debugger interface on the client device 312 isno longer available to control execution of the script, and in responsethe application module 330 may either terminate the execution of thescript that was being debugged or cause the script to continue runningin a non-debug mode (e.g., a production mode) where it skips remainingbreakpoints and consumes less computing resources on the server device302.

Many different users (e.g., users of multiple client devices 310, 312,and 314) may share the resources of the server device. The applicationmodule 330 may allow multiple users to debug their own transactionswithout affecting each other. In some implementations, the applicationmodule only allows users (e.g., developers) to see and interact withitems related to their current debugging session (e.g., breakpoints,call stack, transactions, or status). The application module 330 mayprevent one developer from seeing or modifying a debug instance ofanother user. Certain special users (e.g., administrators), however, maybe enabled to impersonate another user, open the debugger interface, anddebug transactions generated by the impersonated user.

Because the computing resources (e.g., processor time) on the serverdevice are limited and executing a set of instructions in a debug modemay consume more of the computing resources and/or degrade performancerelative to running in non-debug mode, it may be advantageous to limitthe number of concurrent threads running in a debug mode, such as byserver, by session, or by user. By default, the application module 330may support debugging a limited number (e.g., one fourth of a number ofsemaphores on the instance) of concurrent transactions. Users may, forexample, be limited to one or two debug sessions. Certain special users(e.g., administrators) may be able to specify the number of concurrenttransactions the system can debug by setting a configuration parameter.

FIG. 4 is a flowchart illustrating an example of a technique 400 forexecuting a set of instructions to be debugged via a session with aclient device in an electronic computing and communications system, suchas the system 100 as generally illustrated in FIG. 1. In someimplementations, the technique 400 can be executed using computingdevices, such as the systems, modules, and devices described withrespect to FIGS. 1, 2, and 3. In some implementations, the technique 400can be performed, for example, by executing a machine-readable code,such as instructions or programs written to JavaScript, C, or other suchcomputer programming languages. The steps, or operations, of thetechnique 400 or any other method, process, or algorithm described inconnection with the implementations disclosed herein can be implementeddirectly in hardware, firmware, software executed by hardware,circuitry, or a combination thereof.

The technique 400 may include, when executing a set of instructions in adebug mode, determining (at operation 445), based on a second marker(e.g., a semaphore), that pausing execution of the set of instructionsusing a data structure (e.g., a session data structure) is permittedand, responsive to this determination, pausing (at operation 452)execution of the set of instructions before executing an instructionassociated with a breakpoint, and updating (at operation 450) the secondmarker to indicate that execution of the set of instructions is pausedusing the data structure.

The technique 400 may include receiving (at operation 410) a requestfrom a client device (e.g., the client device 312). In someimplementations, the request may be a command to launch and/or control adebugger instance to execute a set of instructions (e.g., code) in adebug mode. For example, the request received (at operation 410) may bea request to launch a debugger instance that explicitly specifies a setof instructions (e.g., a script) to be run in a debug mode. For example,the request may be to perform a service (e.g., serve a webpage or updatea database record) which causes a server device (e.g., the server device302) receiving (at operation 410) the request to execute a set ofinstructions (e.g., a script) (after obtaining control of the session atoperations 415 and 420) that has been previously marked for execution ina debug mode, for example, by inserting one or more breakpointsassociated with instructions of the set of instructions. In someimplementations, the request is received (at operation 410) by a server(e.g., the server device 302) via a network interface (e.g., the networkcommunication unit 218).

One or more debug control transactions may be executed in order tocontrol a debugged transaction that will execute a set of instructionsassociated with one or more breakpoints in a debug mode and may bepaused. Debug control transactions may utilize the session in the samewas as a debugged transaction that is of primary interest. For example,when a request is received that includes a debug command to resume(e.g., a resume or step command) execution of a debugged transactionthat is paused (e.g., at a breakpoint), the request may cause a debugcontrol transaction to be executed using technique 400. The debugcontrol transaction may execute a set of instructions (at operation 440)that notifies the paused debugged transaction that it should resumeexecution as soon as possible. For example, the debug controltransaction may notify the debugged transaction using a semaphore or byotherwise writing to a data structure shared by the two transactions(e.g., the session data structure). The debugged transaction may thenattempt (at operation 415) to acquire the session lock, but will beprevented because the debug control transaction currently holds thesession access marker that it acquired (at operation 420). The debuggedtransaction will therefore wait (at operation 418) to acquire thatsession lock. The debug control transaction will continue execution ofits instructions to completion (at operation 472), at which point itupdates (at operation 460) the session access marker to release thesession lock. With the session lock now released, the debuggedtransaction is able to acquire the session lock by updating (atoperation 420) the session access marker and proceed with execution ofits set of instructions using the technique 400. In this manner, therequest including the command to resume that was received (at operation410) may cause the debugged transaction to resume execution, using thetechnique 400, of the set of instructions that is associated with onemore breakpoints.

The technique 400 may include determining (at operation 415), based onan access marker, whether a data structure is available for use inexecuting the set of instructions. In some implementations, the datastructure is a session data structure for a session associated with arequest received (at operation 410). For example, the access marker mayinclude a mutex for a session data structure that is associated with arequest received (at operation 410). In some implementations, the accessmarker may include a semaphore for a session data structure that isassociated with a request received (at operation 410).

If (at operation 415) it is determined that the data structure is notavailable for use in executing the set of instructions, a thread thatwill execute the set of instructions may wait (at operation 418) for thedata structure to become available. For example, where the access markerincludes a mutex for a session data structure, a loop may be entered tocontinue checking periodically (at operation 415) if the mutex for thesession data structure is available. For example, where the accessmarker includes a semaphore for a session data structure, a wait oracquire function may be utilized (at operation 418) for the semaphore.

When (at operation 415) it is determined that the data structure is notavailable for use in executing the set of instructions, markers for thesession marker may be updated (at operation 420). In someimplementations, responsive to the determination (at operation 415) thatthe data structure is available, the access marker may be updated (atoperation 420) to indicate that the data structure (e.g., the sessiondata structure) is in use. For example, a mutex for the session datastructure may be locked. For example, a semaphore for the session datastructure may be acquired.

A set of instructions to be executed may be identified (at operation424). For example, responsive to receiving (at operation 410) therequest and taking control of the session, a server device (e.g., theserver device 302) may use an explicit specification in the request toidentify (at operation 424) a set of instructions (e.g., a script) to beexecuted, which may be associated with one or more breakpoints. Forexample, the request may include a command (e.g., resume, step over,step into, or step out) to control a debugger instance already executinga set of instructions in a debug mode on the server receiving (atoperation 410) the request. In some implementations, the request may beto perform a service (e.g., serve a webpage or update a database record)which causes a server device (e.g., the server device 302) receiving (atoperation 410) the request to identify (at operation 424) a set ofinstructions (e.g., a script) to be executed that has been previouslymarked for execution in a debug mode, for example, by inserting one ormore breakpoints associated with instructions of the set ofinstructions. The presence of debug configuration information (e.g., abreakpoint or a debug mode enable flag) associated with (e.g., stored ina database or file with a reference to or in the same location as theset of instructions) the set of instructions to be executed in providingthe requested service may automatically trigger a debugger instance thatis not explicitly called for in the request message that is received (atoperation 410).

It may be determined (at operation 430) that execution of a set ofinstructions will be continued from a paused state (e.g., in response toa resume or step command). For example, this determination may be basedon information in the request received (at operation 410), for example,data identifying a debug command from a user (e.g., resume, step over,step into, step out). For example, this determination may be based oninformation in a notification from a debug control transaction that hasbeen executed in response to the request received (at operation 410).Responsive to the determination (at operation 430) that execution of aset of instructions will be continued from a paused state, a pausemarker may be updated (at operation 430) to indicate that execution ofthe set of instructions is no longer paused using the data structure. Insome implementations, the pause marker may include a semaphore. Forexample, the pause semaphore may be used to keep track of how manythreads are currently paused using the session data structure. In someimplementations, the pause marker for a session is a binary semaphorethat indicates whether a thread using the session is paused. In someimplementations, the pause marker may be updated (at operation 430) byunlocking a mutex included in the pause marker. In some implementations,the pause marker may be updated (at operation 430) by signaling orreleasing a semaphore included in the pause marker.

Execution of the set of instructions may be initiated (at operation432). In some implementations, the set of instructions is a scriptidentified (at operation 424), and execution of the script includesinterpreting instructions of the script using a script interpreterexecuted by a processor (e.g., the processor 202). For example, thescript interpreter may include a debug interface that permits anapplication executed by the processor to pause and continue execution ofthe script by interfacing with the debug interface. For example, ascript identified (at operation 424) may be passed by the applicationmodule 330 to the script module 340 to initiate (at operation 432)execution. For example, a command (e.g., step or resume) may be passedthrough a debug API to the script module 340 to initiate (at operation432) execution of a script previously passed to the script module 340.

A next instruction in the identified (at operation 424) set ofinstructions may then be checked (at operation 435) to determine whetherthere is a breakpoint that should be enforced for the next instruction.In some implementations, a table of breakpoints associated with the setof instructions may be maintained and checked (at operation 435). Insome implementations, breakpoints are associated with a user and can beenforced when that user or another user impersonating that user isexecuting the set of instructions in a debug mode. This may allow manyusers to share and debug a set of instructions (e.g., a script) withoutinterfering with one another. For example, where a breakpoint is found(e.g., in a table of breakpoints) that is associated the nextinstruction, the breakpoint may be checked to determine whether thebreakpoint applies for a user associated with the request received (atoperation 410). In some implementations, a check may be performed todetermine whether a user is permitted to access the next instruction(e.g., has read permissions for a file storing the next instruction). Abreakpoint may be skipped (e.g., as described in relation to thetechniques 700 and/or 800 of FIGS. 7 and 8) if the user is determined tobe not permitted to access the next instruction. For example, theapplication module 330 may determine (at operation 435) whether there isa breakpoint that should be enforced for the next instruction.

If (at operation 435) there is no applicable breakpoint for the nextinstruction, the next instruction may be executed (at operation 440).For example, the next instruction may be executed (at operation 440)when the application module 330 issues a command to the script module340 through a debug API provided by the debug controller 344. Forexample, the script module 340 may use the interpreter 342 to interpretthe next instruction and execute the next instruction.

Next, it may be determined (at operation 441) whether execution of theidentified (at operation 424) set of instructions is complete. Forexample, execution may be completed when the last instruction in the setof instructions (e.g., a script) has been executed. In someimplementations, completion may be determined based on the occurrence ofan external event, for example, a determination that a debuggerinterface on a client device has become unavailable (as described inrelation to the technique 600 of FIG. 6). In some implementations,completion may be triggered by an external command, for example, a haltor reset command from an administrator. If (at operation 441) executionof the set of instructions is not complete, a next instruction may beconsidered by checking (at operation 435) for a breakpoint. For example,a callback function registered by the application module 330 with thescript module 340 may be run to consider the next instruction.

If (at operation 435) there is an applicable breakpoint for the nextinstruction, a pause marker may be checked (at operation 445) todetermine, based on the pause marker, whether pausing execution of theidentified (at operation 424) set of instructions using the datastructure is permitted. In some implementations, the pause marker may bea mutex or a semaphore associated with the session data structure. Someimplementations may determine (at operation 445), based on the pausemarker, whether a number of concurrently paused transactions using thedata structure has exceeded a limit. A system implementing the technique400 (e.g., the server device 302) may impose a limit on the number oftransactions executing sets of instructions (e.g., code, scripts, etc.)that may be paused concurrently using the session data structure. Forexample, the pause marker may include a semaphore that maintains a countof concurrently paused transactions that are using the session datastructure, or, equivalently, a count of available slots for transactionsto pause using the session data structure. For example, this countmaintained in a semaphore may be compared to a limit (e.g., one oranother limit imposed by a system administrator). Some implementationsmay determine (at operation 445), based on the pause marker, whetherthere is a paused execution of instructions using the data structure.For example, a system (e.g., the server device 302) may limit the numberof concurrently paused transactions for the session data structure toone, the pause marker may include a binary semaphore, and examining thebinary semaphore may determine (at operation 445) whether another threador transaction is currently paused using the session data structure. Forexample, the application module 330 may determine (at operation 445),based on the pause marker, whether pausing execution of the identified(at operation 424) set of instructions using the session data structureis permitted.

Responsive to determining (at operation 445) that pausing execution ofthe set of instructions using the data structure is permitted, the pausemarker may be updated (at operation 450) to indicate that execution ofthe first set of instructions is paused using the data structure;execution of the set of instructions may be paused (at operation 452)before executing an instruction associated with the breakpoint underconsideration; and the access marker may be updated (at operation 460)to indicate that the data structure is available.

The pause marker may be updated (at operation 450) by performing a waitor acquire method for a semaphore included in the pause marker. In someimplementations, the pause marker may be updated (at operation 450) bylocking a mutex included in the pause marker. In some implementations,updating (at operation 450) the pause marker includes writing anidentifier of a thread (e.g., the thread executing the identified set ofinstructions in a debug mode) to the pause marker.

For example, execution of the identified set of instructions may bepaused (at operation 452) to provide an opportunity for a user toexamine the debugger state (e.g., variables used by the set ofinstructions) and/or input commands for continued execution in a debugmode. In some implementations, execution of the identified set ofinstructions is paused (at operation 452) by issuing or withholding acommand to a script engine through a debug API. For example, theapplication module 330 may pause (at operation 452) execution of ascript by issuing a command to the script module 340 through its debugAPI provided by the debug controller 344, where the command may causethe script module 340 to enter a pause state. For example, theapplication module 330 may pause (at operation 452) execution of ascript by withholding a command to the script module 340 through itsdebug API provided by the debug controller 344, where the command wouldcause the script module 340 to execute the next instruction.

An indication that the breakpoint was reached may be transmitted (atoperation 454) to the client device for presentation to a user. Forexample, the server device 302 may transmit (at operation 454), via anetwork interface (e.g., the network communication unit 218), anindication to the client device 312 that the breakpoint was reached. Theclient device 312 may be configured to present (e.g., using the webbrowser 322) an indication to a user that the breakpoint was reached.For example, the client device may display a pop-up window notifying auser that the breakpoint was reached and opening or offering to open adebugger interface window to facilitate user debugging of the identifiedset of instructions. In some implementations, a message including theindication may include information about the breakpoint and the currentcall stack for the set of instructions being executed. In someimplementations, the indication is transmitted (at operation 454) afterthe breakpoint is reached and before a new request is received from theclient device. In this manner (e.g., as discussed in relation to thetechnique 500 of FIG. 5), delays from waiting for a client device torequest an update after the breakpoint is reached may be avoided.

After pausing or terminating the execution of the identified set ofinstructions, the access marker may be updated (at operation 460) tomake the data structure available to other threads or transactions. Forexample, this may allow transactions initiated by a user to control thedebugger instance (e.g., resuming, stepping, or retrieving the value ofa variable used by the set of instructions), as well as other unrelateduser transactions, to be processed using a session data structure whilethe execution of the identified set of instructions is paused. In someimplementations, the access marker may be updated (at operation 460) byperforming a signal or release method for a semaphore included in theaccess marker. In some implementations, the access marker may be updated(at operation 450) by unlocking a mutex included in the access marker.

Responsive to the determination (at operation 445) that pausingexecution of the set of instructions using the data structure is notpermitted, the breakpoint may be skipped (at operation 470) by executing(at operation 440) the instruction associated with the breakpointwithout pausing execution of the identified set of instructions. Forexample, the application module 330 may skip (at operation 470) thebreakpoint by issuing a command to the script module 340 through thedebug API provided by the debug controller 344, where the command causesthe script module 340 to execute the next instruction, which isassociated with the breakpoint.

If (at operation 441) execution of the set of instructions is complete,execution of the identified set of instructions may be terminated (atoperation 472). For example, the application module 330 may terminate(at operation 472) execution of the set of instructions (e.g., a script)by issuing a termination command to the script module 340. Aftertermination (at operation 472) of execution, the session access markermay be updated (at operation 460).

In some implementations, the technique 400 includes checking (atoperation 445) a marker associated with a session to determine ifanother thread using the session is paused, and, if another thread usingthe session is paused, executing (at operation 440) the set ofinstructions without pausing, and, if no other thread using the sessionis paused, executing (at operation 440) the set of instructions until aninstruction of the set of instructions associated with a breakpoint isreached, wherein execution of the set of instructions is paused (atoperation 452) responsive to reaching the breakpoint.

In some implementations (not shown in FIG. 4), the technique 400 may bemodified so that a debugged transaction continues to hold a pause markerafter it resumes execution and until the debugged transaction isterminated. Instead of updating (at operation 430) the pause marker whena paused transaction resumes, the pause marker may remain locked by adebugged transaction until that debugged transaction is terminated. Forexample, responsive to terminating (at operation 472) execution of thefirst set of instructions, a debugged transaction may update the pausemarker to indicate that execution of the its set of instructions is nolonger paused using the data structure. For example, the pause markermay be locked when a debugged transaction using the session reaches afirst breakpoint during its execution and the pause marker may remainlocked until that transaction completes execution or is otherwiseterminated. This example handling of the pause marker may preventanother debugged transaction from locking the pause marker while thefirst debugged transaction is executing between subsequent breakpoints,and ensure that the first debugged transaction is able to finishdebugging in the expected way once its first breakpoint has beenreached.

Although the technique 400 is shown as a series of operations forclarity, implementations of the technique 400 or any other technique,process, or algorithm described in connection with the implementationsdisclosed herein can be performed in various orders or concurrently.Additionally, operations in accordance with this disclosure can beperformed with other operations not presented and described herein. Forexample, the technique 600 of FIG. 6 may be used to terminate executionof the identified set of instructions responsive to determining that adebugger interface on the client device (e.g., the client device 312) isno longer available to control execution of the identified set ofinstructions. For example, the technique 600 of FIG. 6 may be used to,responsive to a determination that the session associated with therequest has terminated, skip one or more remaining breakpointsassociated with the identified set of instructions. For example, thetechnique 800 of FIG. 8 may be used to receive a request from the clientdevice (e.g., the client device 312) to step into a function from theset of instructions; determine that a user (e.g., a user associated withthe request) is not permitted to access the function (e.g., because theuser lacks read permission for the file in which the a set ofinstructions for the function is stored); and, responsive to thedetermination that the user is not permitted to access the function,step over the function by executing the function without pausingexecution of the set of instructions. For example, in an implementation,when it is determined (at operation 445) that pausing execution of theset of instructions using the data structure is not permitted, anyremaining breakpoints associated with the identified set of instructionsmay be skipped by continuing execution of the first set of instructionsin a non-debug mode (e.g., a production mode), where all breakpoints aredisabled. For example, in an implementation, for threads executing a setof instructions that is not being debugged, operation 435 may be omittedand execution of the set of instructions may proceed to completionwithout checking for breakpoints. For example, in an implementation, forthreads executing a set of instructions that is not being debugged,operation 430 may be omitted. For example, a debug control transaction,rather than the debugged transaction itself, may update (at operation430) the pause marker after or as part of notifying the debuggedtransaction that it should resume execution in response a requestincluding a resume command received (at operation 410) from a clientdevice. Furthermore, one or more aspects of the systems and techniquesdescribed herein can be omitted.

FIG. 5 is a flowchart illustrating an example of a technique 500 fortransmitting, to a client device, an indication that a breakpoint wasreached when execution pauses at the breakpoint in an electroniccomputing and communications system, such as the system 100 as generallyillustrated in FIG. 1. In some implementations, the technique 500 can beexecuted using computing devices, such as the systems, modules, anddevices described with respect to FIGS. 1, 2, and 3. In someimplementations, the technique 500 can be performed, for example, byexecuting a machine-readable code, such as instructions or programswritten to JavaScript, C, or other such computer programming languages.The steps, or operations, of the technique 500 or any other method,process, or algorithm described in connection with the implementationsdisclosed herein can be implemented directly in hardware, firmware,software executed by hardware, circuitry, or a combination thereof.

The technique 500 may include receiving (at operation 510) a requestfrom a client device (e.g., the client device 312), identifying (atoperation 520) a set of instructions (e.g., a script) to be executed,initiating (at operation 530) execution of the identified set ofinstructions, pausing (at operation 540) the execution at an instructionassociated with a breakpoint, and transmitting (at operation 550), tothe client device, a message that indicates that a breakpoint has beenreached. For example, the message that indicates that a breakpoint hasbeen reached may be transmitted (at operation 550) based on theserver-side event of pausing execution on the breakpoint, rather than inresponse to a later request from the client device for an update. Insome implementations, triggering the sending of an update message basedon a server-side debugger event of a breakpoint being reached may offerperformance advantages. For example, in some implementations, the delayassociated with waiting for a client query with a request after thebreakpoint is reached can be avoided, reducing the latency of a debuggerinstance for a set of instructions executed on the server and debuggedfrom the client device. In some implementations, less computingresources (e.g., processor time on a server device and/or a clientdevice and/or network bandwidth) are consumed compared to a system thatrelies on the client device polling the server device to retrieveupdates on the state of a debugger instance.

The technique 500 may include receiving (at operation 510) a requestfrom a client device (e.g., the client device 312). In someimplementations, the request may be a command to launch and/or control adebugger instance to execute a set of instructions (e.g., code) in adebug mode. For example, the request received (at operation 510) may bea request to launch a debugger instance that explicitly specifies a setof instructions (e.g., a script) to be run in a debug mode. For example,responsive to receiving (at operation 510) the request, a server device(e.g., the server device 302) may use this specification in the requestto identify (at operation 520) a set of instructions (e.g., a script) tobe executed, which may be associated with one or more breakpoints. Forexample, the request may include a command (e.g., resume, step over,step into, or step out) to control a debugger instance already executinga set of instructions in a debug mode on the server receiving (atoperation 510) the request. In some implementations, the request may beto perform a service (e.g., serve a webpage or update a database record)which causes a server device (e.g., the server device 302) receiving (atoperation 510) the request to identify (at operation 520) a set ofinstructions (e.g., a script) to be executed that has been previouslymarked for execution in a debug mode, for example, by inserting one ormore breakpoints associated with instructions of the set ofinstructions. The presence of debug configuration information (e.g., abreakpoint or a debug mode enable flag) in a file storing the set ofinstructions to be executed in providing the requested service mayautomatically trigger a debugger instance that is not explicitly calledfor in the request message that is received (at operation 510). In someimplementations, the request is received (at operation 510) by a server(e.g., the server device 302) via a network interface (e.g., the networkcommunication unit 218).

Execution of the set of instructions may be initiated (at operation530). In some implementations, the set of instructions is a scriptidentified (at operation 520), and execution of the script includesinterpreting instructions of the script using a script interpreterexecuted by a processor (e.g., the processor 202). For example, thescript interpreter may include a debug interface that permits anapplication executed by the processor to pause and continue execution ofthe script by interfacing with the debug interface. For example, ascript identified (at operation 520) may be passed by the applicationmodule 330 to the script module 340 to initiate (at operation 530)execution. For example, a command (e.g., step or resume) may be passedthrough a debug API to the script module 340 to initiate (at operation530) execution of a script previously passed to the script module 340.

Execution of the identified (at operation 520) set of instructions maybe paused (at operation 540) when an instruction of the identified setof instructions associated with a breakpoint is reached. For example, auser may have previously associated a breakpoint with an instruction byopening a file (e.g., a text file) storing the instruction in a codeediting interface (e.g., a text editor or a coding pane of a debuggerinterface) and clicking the gutter (e.g., a line along the left columnof a display of text file contents) next to a line in the filecorresponding to the instruction. This user action may set a breakpointand associate the breakpoint with the instruction. In someimplementations, the breakpoint and its association with the instructionmay be encoded in a retrieved from a table of breakpoints stored indebug metadata included in or associated with a file encoding the set ofinstructions (e.g., a script).

For example, execution of the identified set of instructions may bepaused (at operation 540) to provide an opportunity for a user toexamine the debugger state (e.g., variables used by the set ofinstructions) and/or input commands for continued execution in a debugmode. In some implementations, execution of the identified set ofinstructions is paused (at operation 540) by issuing or withholding acommand to a script engine through a debug API. For example, theapplication module 330 may pause (at operation 540) execution of ascript by issuing a command to the script module 340 through its debugAPI provided by the debug controller 344, where the command may causethe script module 340 to enter a pause state. For example, theapplication module 330 may pause (at operation 540) execution of ascript by withholding a command to the script module 340 through itsdebug API provided by the debug controller 344, where the command wouldcause the script module 340 to execute the next instruction.

As a precondition for pausing (at operation 540) at the breakpoint, aserver device (e.g., the server device 302) may determine, based on apause marker, that pausing execution using a session data structure ispermitted. For example, the pause marker may include a mutex or asemaphore (e.g., a binary semaphore), which may be used to limit (e.g.,to one at a time) the number of transactions or threads that may beconcurrently paused (at operation 540) using the session data structure.For example, the technique 400 may be used to determine (at operation445) whether, based on a pause marker, pausing execution using a sessiondata structure is permitted. For example, as a precondition for pausing(at operation 540) at the breakpoint, a server device (e.g., the serverdevice 302) may determine (at operation 445), based on a pause marker,that a number of concurrently paused transactions using a session datastructure has not exceeded a limit.

A message that indicates that a breakpoint has been reached may betransmitted (at operation 550) to the client device. In someimplementations, the message is transmitted (at operation 550) after thefirst breakpoint is reached and before a new request is received fromthe client device. For example, the message that indicates that abreakpoint has been reached may be transmitted via a WebSocket that waspreviously established between the client device (e.g., the clientdevice 312) and a server device (e.g., the server device 302) that isimplementing the technique 500. For example, the message that indicatesthat a breakpoint has been reached may be transmitted via a channelestablished by long polling from the client device (e.g., the clientdevice 312). For example, the message that indicates that a breakpointhas been reached may be transmitted (at operation 550) to the clientdevice (e.g., the client device 312) from a server device (e.g., theserver device 302) via a network interface (e.g., the networkcommunication unit 218).

Responsive to the message that indicates that a breakpoint has beenreached, the client device (e.g., the client device 312) may display apop-up window (e.g., in the web browser 322) to alert the user that thedebugger instance on a server device has paused and is ready to bedebugged through a debugger interface presented on the client device. Insome implementations, the client device (e.g., the client device 312)may display a debugger interface (e.g., including the display region 910of FIG. 9) to a user and transmit subsequent requests to the serverdevice (e.g., the server device 302) to gather more information from adebugger instance (e.g., examine the values of variables used by theidentified (at operation 520) set of instructions) and/or to controlcontinued execution of the identified (at operation 520) set ofinstructions.

Although the technique 500 is shown as a series of operations forclarity, implementations of the technique 500 or any other technique,process, or algorithm described in connection with the implementationsdisclosed herein can be performed in various orders or concurrently.Additionally, operations in accordance with this disclosure can beperformed with other operations not presented and described herein. Forexample, the technique 600 of FIG. 6 may be used to terminate executionof the identified (at operation 520) set of instructions responsive todetermining that a debugger interface on the client device (e.g., theclient device 312) is no longer available to control execution of theidentified set of instructions. For example, responsive to thedetermination that execution of the identified (at operation 520) set ofinstructions will be continued from a paused state, a pause marker maybe updated (at operation 430) to indicate that execution of the set ofinstructions is no longer paused using a session data structure.Furthermore, one or more aspects of the systems and techniques describedherein can be omitted.

FIG. 6 is a flowchart illustrating an example of a technique 600 forterminating or modifying the execution of a set of instructions runningin a debug mode upon determining that a debugger interface on a clientdevice has become unavailable to control execution of the set ofinstructions in an electronic computing and communications system, suchas the system 100 as generally illustrated in FIG. 1. In someimplementations, the technique 600 can be executed using computingdevices, such as the systems, modules, and devices described withrespect to FIGS. 1, 2, and 3. In some implementations, the technique 600can be performed, for example, by executing a machine-readable code,such as instructions or programs written to JavaScript, C, or other suchcomputer programming languages. The steps, or operations, of thetechnique 600 or any other method, process, or algorithm described inconnection with the implementations disclosed herein can be implementeddirectly in hardware, firmware, software executed by hardware,circuitry, or a combination thereof.

The technique 600 may include receiving (at operation 610) a requestfrom a client device (e.g., the client device 312), identifying (atoperation 620) a set of instructions (e.g., a script) to be executed,initiating (at operation 630) execution of the identified set ofinstructions, determining (at operation 640) that a debugger interfaceon a client device (e.g., the client device 312) is no longer availableto control execution of the identified set of instructions, and,responsive to this determination, either continuing (at operation 650)execution of the identified (at operation 620) set of instructions in anon-debug mode or terminating (at operation 660) execution of theidentified (at operation 620) set of instructions. In someimplementations, triggering the termination or modification of theexecution of a set of instructions upon the event of a disconnectiondetected by the server may offer performance advantages. For example, insome implementations, less computing resources (e.g., processor timeand/or memory on a server device and/or network bandwidth) are consumedcompared to a system that allows a set of instructions to be executed ina debug mode and potentially paused while a user is unavailable to acton the debug information and/or terminate a requested debug transaction.

The technique 600 may include receiving (at operation 610) a requestfrom a client device (e.g., the client device 312). In someimplementations, the request may be a command to launch and/or control adebugger instance to execute a set of instructions (e.g., code) in adebug mode. For example, the request received (at operation 610) may bea request to launch a debugger instance that explicitly specifies a setof instructions (e.g., a script) to be run in a debug mode. For example,responsive to receiving (at operation 610) the request, a server device(e.g., the server device 302) may use this specification in the requestto identify (at operation 620) a set of instructions (e.g., a script) tobe executed, which may be associated with one or more breakpoints. Forexample, the request may include a command (e.g., resume, step over,step into, or step out) to control a debugger instance already executinga set of instructions in a debug mode on the server receiving (atoperation 610) the request. In some implementations, the request may beto perform a service (e.g., serve a webpage or update a database record)which causes a server device (e.g., the server device 302) receiving (atoperation 610) the request to identify (at operation 620) a set ofinstructions (e.g., a script) to be executed that has been previouslymarked for execution in a debug mode, for example, by inserting one ormore breakpoints associated with instructions of the set ofinstructions. The presence of debug configuration information (e.g., abreakpoint or a debug mode enable flag) in a file storing the set ofinstructions to be executed in providing the requested service mayautomatically trigger a debugger instance that is not explicitly calledfor in the request message that is received (at operation 610). In someimplementations, the request is received (at operation 610) by a server(e.g., the server device 302) via a network interface (e.g., the networkcommunication unit 218).

Execution of the set of instructions may be initiated (at operation630). In some implementations, the set of instructions is a scriptidentified (at operation 620), and execution of the script includesinterpreting instructions of the script using a script interpreterexecuted by a processor (e.g., the processor 202). For example, thescript interpreter may include a debug interface that permits anapplication executed by the processor to pause and continue execution ofthe script by interfacing with the debug interface. For example, ascript identified (at operation 620) may be passed by the applicationmodule 330 to the script module 340 to initiate (at operation 630)execution. For example, a command (e.g., step or resume) may be passedthrough a debug API to the script module 340 to initiate (at operation630) execution of a script previously passed to the script module 340.

The technique 600 may include determining (at operation 640) that adebugger interface on the client device (e.g., the client device 312) isno longer available to control execution of the identified (at operation620) set of instructions. A debugger interface (e.g., including thedisplay region 910) on the client device may become unavailable to theserver executing the identified (at operation 620) set of instructionsfor a variety of reasons. For example, a user may input an exit commandin the debugger interface, causing the debugger interface to beterminated and become unavailable. For example, a web browser window ortab displaying the debugger interface may be closed, causing thedebugger interface to be terminated and become unavailable. For example,a user may logout of a session with the server that is used by thedebugger interface, causing the session to terminate and the debuggerinterface to become unavailable. For example, a user may logout of asession with the server that is used by the debugger interface, causingthe session to terminate and the debugger interface to becomeunavailable. For example, the client device may be shut down or crash,causing the debugger interface to effectively terminate and to becomeunavailable. For example, a disruption in a network used forcommunications between the client device and the server may preventcommunications for an extended period of time, causing the debuggerinterface become unavailable.

A determination (at operation 640) that a debugger interface on theclient device (e.g., the client device 312) is no longer available maybe based on receiving a message that indicates the debugger interface onthe client device is no longer available. For example, the client devicemay send a message to the server indicating that the debugger interfaceis being terminated as part of its procedure for terminating thedebugger interface (e.g., in response to a user exit command of theclose of a browser window or tab). For example, the client device maysend a message to the server indicating that the debugger interface isbeing terminated via a persistent messaging channel (e.g., anasynchronous messaging bus) that is associated with the debuggerinterface on the client device and the debugger instance on the server.In some implementations, a determination (at operation 640) that adebugger interface on the client device (e.g., the client device 312) isno longer available may be based on the expiration of timer. Forexample, a timeout timer associated with a session may expire if theclient device becomes unavailable for an extended period of time (e.g.,due to a crash of the client device or a network disruption), causingthe session to terminate. For example, a timeout timer associated with apersistent messaging channel (e.g., an asynchronous messaging bus),which is associated with the debugger interface on the client device andthe debugger instance on the server, may expire if the client devicebecomes unavailable for an extended period of time.

A server device (e.g., the server device 302) may determine (atoperation 640) that a session associated with the received (at operation610) request has terminated. The determination (at operation 640) that asession associated with the request has been terminated may be based ona message from a networking stack running on a server device (e.g., theserver device 302) indicating that the session has been terminated. Thesession may have been terminated because, for example, a message wasreceived from the client device (e.g., terminating the session), a timerexpired (e.g., a timeout condition), or some other event occurredindicating that the session should be terminated. For example, a sessionmay be terminated after a user of the client device closes a web browserwindow (e.g., in the web browser 322) that is associated with thesession, the client device shuts down or crashes, or networkdisturbances prevent network communications between a server device andthe client device for an extended period of time.

In some implementations, a user (e.g., an administrator) may configure aserver device (e.g., the server device 302) and/or an application node(e.g., the application module 330) to modify or terminate the executionof a set of instructions that is being executed in a debug mode when adebugger interface on a client device controlling the execution of theset of instructions becomes unavailable (e.g., due to a disconnection).For example, an administrator for a server device (e.g., the serverdevice 302) may set a configuration parameter to make this selection forall debug transactions running on the server device. In someimplementations, an administrator may configure the behavior, for thecase where a controlling debugger interface becomes unavailable, ofthese debugger instances differently depending on the type of serviceprovided using the affected set of instructions (e.g., a script). Forexample, an administrator may configure a server device (e.g., theserver device 302) to continue (at operation 650) execution in aproduction mode of scripts being executed to update a database. Forexample, an administrator may configure a server device (e.g., theserver device 302) to terminate (at operation 660) scripts beingexecuted to serve webpages.

Responsive to the determination (at operation 640) that a debuggerinterface on the client device is no longer available, if (at operation645) the system is configured to continue executing sets of instructions(e.g., scripts) in a non-debug mode upon termination of an associateddebugger instance, then execution of the identified (at operation 620)set of instructions may continue in a non-debug mode (e.g., a productionmode) and remaining breakpoints associated with the identified (atoperation 620) set of instructions may be skipped (at operation 650).For example, responsive to the determination that a session associatedwith the received (at operation 610) request has terminated, one or moreremaining breakpoints associated with the identified (at operation 620)set of instructions may be skipped (at operation 650). For example, theapplication module 330 may continue (at operation 650) execution of theset of instructions (e.g., a script) by issuing a command to the scriptmodule 340 through the debug API provided by the debug controller 344 todisable the debug features for the remaining execution of the set ofinstructions by the script module 340. In some implementations,continuing (at operation 650) execution of the set of instructions in anon-debug mode may prevent indeterminate results (e.g., a partial,incomplete update of a record in a database) that may arise fromabruptly halting execution of a script.

Responsive to the determination (at operation 640) that a debuggerinterface on the client device is no longer available, if (at operation645) the system is configured to halt execution of sets of instructions(e.g., scripts) upon termination of an associated debugger instance,then execution of the identified (at operation 620) set of instructionsmay be terminated (at operation 660). In some implementations, debuggingof the identified (at operation 620) set of instructions by a scriptinterpreter may be terminated (at operation 660) by sending a command toa debug interface of a script interpreter to stop interpreting ordebugging the identified set of instructions. For example, theapplication module 330 may terminate (at operation 660) execution of ascript by sending a command to the script module 340 via the debug APIprovided by the debug controller 344, where the command causes thescript module to stop interpreting the script using the interpreter 342or debugging the script. In some implementations, terminating (atoperation 660) execution of a set of instructions (e.g., a script) thatwas being debugged but is no longer being actively debugged may conservecomputing resources (e.g., memory or processor time on a server device).

Although the technique 600 is shown as a series of operations forclarity, implementations of the technique 600 or any other technique,process, or algorithm described in connection with the implementationsdisclosed herein can be performed in various orders or concurrently.Additionally, operations in accordance with this disclosure can beperformed with other operations not presented and described herein. Forexample, the technique 500 of FIG. 5 may be used to pause (at operation540) execution of the identified (at operation 620) set of instructionswhen an instruction of the set of instructions associated with abreakpoint is reached and, after the breakpoint is reached and before anew request is received from the client device, transmit (at operation550), to the client device, a message that indicates that a breakpointhas been reached. For example, the technique 400 of FIG. 4 may be usedto execute the identified (at operation 620) set of instructions in adebug mode prior to determining (at operation 640) that a debuggerinterface on the client device is no longer available. For example, thetechniques 700 and 800 of FIGS. 7 and 8 may be used to execute theidentified (at operation 620) set of instructions in a debug mode whilemaintaining security for the set of instructions prior to determining(at operation 640) that a debugger interface on the client device is nolonger available. Furthermore, one or more aspects of the systems andtechniques described herein can be omitted.

FIG. 7 is a flowchart illustrating an example of a technique 700 forcontrolling access to sections of a set of instructions associated withbreakpoints while running a debugger in an electronic computing andcommunications system, such as the system 100 as generally illustratedin FIG. 1. In some implementations, the technique 700 can be executedusing computing devices, such as the systems, modules, and devicesdescribed with respect to FIGS. 1, 2, and 3. In some implementations,the technique 700 can be performed, for example, by executing amachine-readable code, such as instructions or programs written toJavaScript, C, or other such computer programming languages. The steps,or operations, of the technique 700 or any other method, process, oralgorithm described in connection with the implementations disclosedherein can be implemented directly in hardware, firmware, softwareexecuted by hardware, circuitry, or a combination thereof.

Users may not have permission to read all of the source code for theservices they are able to access on a server. For example, the sourcecode for certain functions that users utilize via an API may be hidden,for example, to protect against network security threats or to protecttrade secrets. In most circumstances, a user sets a breakpoint by firstaccessing a source code file, so, in the normal course, a user shouldnot be able to set breakpoints at instructions they lack permission toread. However, sometimes permissions change over time, and a user mayinadvertently retain a breakpoint in code they no longer have access toread. Also, there may be ways to hack a breakpoint table to gain accessto code stored in files the user lacks permission to read. For example,the technique 700 may provide another level of security to preventinadvertent or malicious access to instructions without permission usingbreakpoints and a debugger instance on a server.

The technique 700 may include executing (at operation 710) a set ofinstructions and reaching a breakpoint; determining (at operation 720)whether a user has permission to access an instruction associated withthe breakpoint; and, if (at operation 725) the user has permission,pausing (at operation 730) execution of the set of instructions at thebreakpoint, or, if (at operation 725) the user does not have permission,continuing (at operation 740) execution of the set of instructions byskipping the breakpoint. In some implementations, by continuingexecution and skipping a breakpoint associated with an instruction thata user lacks permission to read, the security of portions of the set ofinstructions (e.g., a script) may be protected.

A set of instructions may be executed (at operation 710) in a debug modeuntil the next instruction is associated with a breakpoint. For example,the technique 400 of FIG. 4 may be implemented by a server device (e.g.,the server device 302) to execute the set of instructions (e.g., ascript) in a debug mode in response to a request from a client device(e.g., the client device 312).

The technique 700 may include determining (at operation 720) whether auser is permitted to access an instruction of the set of instructionsthat is associated with the breakpoint. For example, the instructionassociated with the breakpoint may be stored in a file (e.g., a textfile) that is associated with user access permission (e.g., permissionto read, write, and/or execute the file). In some implementations, auser associated with a request (e.g., a user account used to make therequest) from a client device that caused the set of instructions to beexecuted is considered. In some implementations, a table of accesspermissions may be maintained in a datacenter (e.g., the datacenter108). The table of access permissions may indicate which users havepermission to access (e.g., to read) particular files or directories.For example, a table of access permissions may be stored on a serverdevice (e.g., on the server device 302 in the memory 206). For example,a table of access permissions may be stored on a database server (e.g.,on the database server 116) and consulted via network communicationsfrom a server device (e.g., the server device 302). In someimplementations, the table of access permissions is checked using anidentifier for the user being considered and an identifier for the filein which the instruction associated with the breakpoint is stored todetermine (at operation 720) whether the user is permitted to access theinstruction. In some implementations, an access permissions list for afile storing the instruction associated with the breakpoint is storedwith the file. For example, information classifying or identifying auser associated with a request that causes the set of instructions to beexecuted may be checked against an access permissions list for the fileto determine (at operation 720) whether the user is permitted to accessthe instruction associated with the breakpoint.

If (at operation 725) the user has permission to access the instructionassociated with the breakpoint, then execution of the set ofinstructions may be paused (at operation 730) to provide an opportunityfor the user to read the file in which the instruction associated withthe breakpoint is stored, examine the debugger state (e.g., variablesused by the set of instructions), and/or input commands for continuedexecution in a debug mode. For example, a copy of the file storing theinstruction associated with the breakpoint may be sent to a clientdevice (e.g., the client device 312) after the execution is paused (atoperation 730) to allow the user to review instructions in the file. Insome implementations, execution of the identified set of instructions ispaused (at operation 730) by issuing or withholding a command to ascript engine through a debug API. For example, the application module330 may pause (at operation 730) execution of a script by issuing acommand to the script module 340 through its debug API provided by thedebug controller 344, where the command may cause the script module 340to enter a pause state. For example, the application module 330 maypause (at operation 730) execution of a script by withholding a commandto the script module 340 through its debug API provided by the debugcontroller 344, where the command would cause the script module 340 toexecute the next instruction.

If (at operation 725) the user does not have permission to access theinstruction associated with the breakpoint, then, responsive to thedetermination that the user is not permitted to access the instructionfrom the set of instructions that is associated with the breakpoint, thebreakpoint may be skipped (at operation 740) by executing theinstruction associated with the breakpoint without pausing execution ofthe set of instructions. In some implementations, breakpoints may beassociated with specific users, and a breakpoint for a user may beremoved from the system once it is determined that the user lackspermission to use the breakpoint. For example, the breakpoint may beremoved or disassociated from the file storing the instructionassociated with the breakpoint. For example, the breakpoint may bedisassociated from the user.

Although the technique 700 is shown as a series of operations forclarity, implementations of the technique 700 or any other technique,process, or algorithm described in connection with the implementationsdisclosed herein can be performed in various orders or concurrently.Additionally, operations in accordance with this disclosure can beperformed with other operations not presented and described herein. Forexample, the technique 600 of FIG. 6 may be used to terminate executionof the identified set of instructions responsive to determining that adebugger interface on the client device (e.g., the client device 312) isno longer available to control execution of the identified set ofinstructions. For example, the technique 600 of FIG. 6 may be used to,responsive to a determination that the session associated with therequest has terminated, skip one or more remaining breakpointsassociated with the identified set of instructions. Furthermore, one ormore aspects of the systems and techniques described herein can beomitted.

FIG. 8 is a flowchart illustrating an example of a technique 800 forcontrolling access to a set of instructions in functions while running adebugger in an electronic computing and communications system, such asthe system 100 as generally illustrated in FIG. 1. In someimplementations, the technique 800 can be executed using computingdevices, such as the systems, modules, and devices described withrespect to FIGS. 1, 2, and 3. In some implementations, the technique 800can be performed, for example, by executing a machine-readable code,such as instructions or programs written to JavaScript, C, or other suchcomputer programming languages. The steps, or operations, of thetechnique 800 or any other method, process, or algorithm described inconnection with the implementations disclosed herein can be implementeddirectly in hardware, firmware, software executed by hardware,circuitry, or a combination thereof.

Users may not have permission to read all of the source code for theservices they are able to access on a server. For example, the sourcecode for certain functions that users utilize via an API may be hidden,for example, to protect against network security threats or to protecttrade secrets. For example, the technique 800 may provide security bypreventing inadvertent or malicious access to instructions withoutpermission using the stepping controls of a debugger instance on aserver.

The technique 800 may include receiving (at operation 810) a requestfrom a client device that includes a step into function debug command;determining (at operation 820) whether a user has permission to access afunction associated with the step into command; and, if (at operation825) the user has permission, stepping into (at operation 830) thefunction from the set of instructions, or, if (at operation 825) theuser does not have permission, continuing (at operation 840) executionof the set of instructions by stepping over the function. In someimplementations, by stepping over a function that a user lackspermission to read, the security of portions of the set of instructions(e.g., a script) may be protected.

A request is received (at operation 810) from a client device (e.g., theclient device 312). The request may include a step into command that, ifperformed, would cause a debugger instance to pause execution at aninstruction stored in a file different from the file currently beingdisplayed to a user on the client device (e.g., displayed in the codingpane 920 of FIG. 9). For example, the debugger instance may have beeninstantiated and operated to implement the technique 400 of FIG. 4 toexecute a set of instructions in a debug mode on a server device (e.g.,the server device 302), which received (at operation 810) the requestvia a network interface (e.g., the network communication unit 218). Forexample, a request received (at operation 810) from the client devicemay be a request to step into a set of instructions (e.g., a function ormethod) from a larger set of instructions being executed in a debugmode.

The technique 800 may include determining (at operation 820) whether auser is permitted to access a subset of instructions (e.g., a functionor method) from a set of instructions being executed in a debug mode.For example, the subset of instructions (e.g., a function) may be storedin a file (e.g., a text file) that is associated with user accesspermission (e.g., permission to read, write, and/or execute the file).In some implementations, a user associated with the request (e.g., auser account used to make the request) from the client device isconsidered. In some implementations, a table of access permissions maybe maintained in a datacenter (e.g., the datacenter 108). The table ofaccess permissions may indicate which users have permission to access(e.g., to read) particular files or directories. For example, a table ofaccess permissions may be stored on a server device (e.g., on the serverdevice 302 in the memory 206). For example, a table of accesspermissions may be stored on a database server (e.g., on the databaseserver 116) and consulted via network communications from a serverdevice (e.g., the server device 302). In some implementations, the tableof access permissions is checked using an identifier for the user beingconsidered and an identifier for the file in which the subset ofinstructions (e.g., a function) is stored to determine (at operation820) whether the user is permitted to access the subset of instructions.In some implementations, an access permissions list for a file storingthe subset of instructions (e.g., a function) is stored with the file.For example, information classifying or identifying a user associatedwith the request may be checked against the access permissions list forthe file to determine (at operation 820) whether the user is permittedto access the subset of instructions (e.g., a function).

If (at operation 825) the user has permission to access the subset ofinstructions (e.g., a function) implicated by the request, then adebugger instance may step into (at operation 730) the subset ofinstructions (e.g., a function) implicated by the request. For example,execution of the set of instructions may be paused at a firstinstruction of the subset of instructions to provide an opportunity forthe user to read the file in which the subset of instructions is stored,examine the debugger state (e.g., variables used by the set ofinstructions), and/or input commands for continued execution in a debugmode. For example, a copy of the file storing the subset of instructions(e.g., a function) may be sent to a client device (e.g., the clientdevice 312) after the execution is paused (at operation 830) to allowthe user to review instructions in the file. In some implementations,execution of the identified set of instructions is paused (at operation830) by issuing or withholding a command to a script engine through adebug API. For example, the application module 330 may pause (atoperation 830) execution of a script by issuing a command to the scriptmodule 340 through its debug API provided by the debug controller 344,where the command may cause the script module 340 to enter a pausestate. For example, the application module 330 may pause (at operation830) execution of a script by withholding a command to the script module340 through its debug API provided by the debug controller 344, wherethe command would cause the script module 340 to execute the nextinstruction.

If (at operation 825) the user does not have permission to access thesubset of instructions (e.g., a function) implicated by the request,then, responsive to the determination that the user is not permitted toaccess the subset of instructions, the subset of instructions may bestepped over (at operation 740) by executing the subset of instructionswithout pausing execution of the set of instructions. For example, theuser associated with the request may be denied read access to the filestoring the subset of instructions (e.g., a function) by stepping over(at operation 840) the subset of instructions.

Although the technique 800 is shown as a series of operations forclarity, implementations of the technique 800 or any other technique,process, or algorithm described in connection with the implementationsdisclosed herein can be performed in various orders or concurrently.Additionally, operations in accordance with this disclosure can beperformed with other operations not presented and described herein. Forexample, the technique 600 of FIG. 6 may be used to terminate executionof the identified set of instructions responsive to determining that adebugger interface on the client device (e.g., the client device 312) isno longer available to control execution of the identified set ofinstructions. For example, the technique 600 of FIG. 6 may be used to,responsive to a determination that the session associated with therequest has terminated, skip one or more remaining breakpointsassociated with the identified set of instructions. Furthermore, one ormore aspects of the systems and techniques described herein can beomitted.

FIG. 9 is a diagram of an example display region 910 generated forpresenting a debugger interface. For example, the display region 910 maybe generated by a client device (e.g., the client device 312) forpresentation (e.g., in the web browser 322) to a user of the clientdevice based on data transmitted by a server (e.g., the server device302) that is running a debugger instance controlled based on requestsreceived from the client device. For example, the display region 910 maybe displayed in a user interface (e.g., the user interface 220) of theclient device. In some implementations, the display region 910 displaysinformation about, for example, breakpoints; the call stack and linenumber of a currently executing script line; and details about variablesand transactions.

The display region 910 may include a coding pane 920 that may display aportion of a set of instructions (e.g., a script) that is being executedin a debug mode on the server. When execution of the set of instructionsis paused, the coding pane 920 may also include a pointer or othermarking indicating at which instruction in the set of instructions theexecution is currently paused. The display region 910 may include acoding pane header 922 that displays a script type and name of a scriptshown in the coding pane 920. The display region 910 may include agutter 924 that shows breakpoints that have been set in the script usingicons overlaid in the coding pane 920 to the left of lines correspondingto instructions in the script that have been associated withbreakpoints.

The display region 910 may include a breakpoints list 926 that displaysa list of the breakpoints set by script type, script name, and linenumber. A debugger instance may update this list as a user adds orremoves breakpoints. The display region 910 may include a call stack 928that displays a list of script calls that preceded or invoked thecurrent instruction or line number. The call stack 928 information maybe updated when a debugger instance pauses at a breakpoint. The displayregion 910 may include a transaction details portion 930 that displaysinformation about the current transaction. The transaction detailsportion 930 information may be updated when a debugger instance pauseson a breakpoint. For example, the transaction details portion 930 mayinclude the display region 1010 of FIG. 10.

The display region 910 may include a local variables portion 932 thatdisplays a list of local scope (e.g., JavaScript) variable names andtheir values. The local variables portion 932 information may be updatedwhen a debugger instance pauses on a breakpoint. The display region 910may include a closures portion 934 that displays a list of global scope(e.g., JavaScript) variable names and their values set by functionclosure. The closures portion 934 information may be updated when adebugger instance pauses on a breakpoint. The display region 910 mayinclude a global variables portion 936 that displays a list of globalscope (e.g., JavaScript) variable names and their values. The globalvariables portion 936 information may be updated when a debuggerinstance pauses on a breakpoint.

The display region 910 may include a debugger status 938 that displaysan indication when a debugger instance is waiting for a breakpoint,paused on a breakpoint, or has encountered an exception. The displayregion 910 may include a user identifier 940 that displays a name of theuser who is controlling the current debugger instance. The displayregion 910 may include a URL 942 that displays an address (e.g., auniform resource locator (URL)) of a currently paused debuggertransaction, which may be used to access debug state information for adebugger running on the server.

The display region 910 may include command icons 950 that enable theuser to select commands to be issued in requests sent to the serverrunning a debugger instance. The command icons 950 may include a disabledebugging icon that stops any current debugging instance and/or disablesa debug mode for the current user. The debugger instance does not pauseexecution of the script on breakpoints for the current user until thedebugger instance is restarted. The command icons 950 may include aresume script execution icon that advances from the current breakpointto the next breakpoint. If there are no other breakpoints, the scriptruns to completion. The command icons 950 may include a step over nextfunction call icon that advances to the next evaluated line of thescript based on current conditions. The debugger instance may skip anyinstructions that do not need to run because their conditions are notmet. The command icons 950 may include a step into next function callicon that advances to the first line of executed code within a functionor method call. Stepping into a method may update the current positionwithin the call stack. If the user does not have read access to thefunction or method call, then this control may act like a step overcommand instead. The command icons 950 may include a step out of currentfunction icon that exits from the current function or method call andreturns to the calling script from the call stack. If the user is notwithin a function or method call, then this control may act like a stepover command instead.

FIG. 10 is a diagram of an example display region 1010 generated forpresenting debug transaction details for debugging a set of instructions(e.g., a script) running on a server from a client device. The displayregion 1010 may display transaction details for a current paused userdebug transaction. For example, the display region 1010 may be presentedin a dedicated re-sizeable section, for example, in the transactiondetails portion 930 of the display region 910. Information shown in thedisplay region 1010 may be updated when it pauses on a script. Users canuse the display region 1010 to: inspect the URL of the currently pausedtransaction; inspect the request parameters for the currently pausedtransaction; inspect network information about the current transaction;and/or inspect the user and session ID that initiated the debugtransaction.

The display region 1010 may provide a standard set of transactiondetails for developers to debug and troubleshoot sets of instructions,such as scripts. In some implementations, the display region 1010 mayinclude a URL portion 1020 that displays an address (e.g., a URL) of thecurrently paused transaction. The display region 1010 may include arequest parameters portion 1022 that displays a list of requestparameters for this transaction. A transaction may have its own list ofrequest parameters. For example, record transactions may include thefield values used to insert, update, or delete a record. The displayregion 1010 may include an instance portion 1024 that displays a name ofa debugger instance running on a server (e.g., the server device 302).

The display region 1010 may include an address portion 1026 thatdisplays an IP address of the end-user client system (e.g., the clientdevice 312). The display region 1010 may include a session portion 1028that displays a user session ID that identifies a session used tosynchronize a debugger instance state between a server (e.g., the serverdevice 302) and a client (e.g., the client device 312). The displayregion 1010 may include a forward portion 1030 that displays an IPaddress of a load balancer (e.g., the load balancer 110). The displayregion 1010 may include a query count portion 1032 that displays anumber of database queries the debugger instance has made. The displayregion 1010 may include a thread portion 1034 that displays a name of athread running the debugger instance on the server. The display region1010 may include a transaction ID portion 1036 that displays a systemidentifier of the current transaction. The display region 1010 mayinclude a token portion 1038 that displays a token of the currentlypaused transaction. The system may use this token to identify differentdebugger instances running on a server (e.g., the server device 302).The display region 1010 may include a name portion 1040 that displays aname of the currently paused transaction. This name may be used toidentify transactions in logs. The display region 1010 may include aprocessor portion 1042 that displays a name of the processor processingthe current transaction. The display region 1010 may include a methodportion 1044 that displays an HTTP request method that the currentlypaused transaction uses. The display region 1010 may include astart-time portion 1046 that displays a date-time stamp indicating whenthe debugger instance started. The display region 1010 may include apage portion 1048 that displays a current table or user interface pageassociated with the transaction. The display region 1010 may include auser portion 1050 that displays a name of a user who triggered the debugtransaction. The display region 1010 may include a node ID portion 1052that displays a system identifier of the node running the debuggerinstance (e.g., the application node 114).

FIG. 11A is a memory map 1100 showing an example format for a sessiondata structure 1110 that is used to facilitate debugging, from a clientdevice, of a set of instructions running on a server. The session datastructure 1110 may be used to maintain state between requests forongoing communications with a client device (e.g., the client device312) operated by a user.

The session data structure 1110 may be associated with a client device,for example, the session data structure 1110 may include a client deviceidentifier 1112 (e.g., a name or an IP address) for a client deviceconducting the session. The session data structure 1110 may beassociated with a user, for example, the session data structure 1110 mayinclude a user identifier 1114 (e.g., a name or a login) for a userconducting the session.

The session data structure 1110 may be associated with a debuggerinstance, for example, the session data structure 1110 may include adebugger state 1116 for a debugger instance that is being controlledbased on requests received as part of the session. For example, thedebugger state 1116 may include pointers to a set of instructions beingexecuted, a pointer to the next instruction to be executed, names andvalues of variables used by a set of instructions being executed, and/orother data used by a debugger instance. The debugger state 1116 may besynchronized with a corresponding debugger state on the client device(e.g., the client device 312) that is used to present debug informationto a user in a debugger interface (e.g., the display region 910). Insome implementations, the debugger state 1116 is synchronized between aclient and a server responsive to the occurrence of a pause event on theserver executing a set of instructions (e.g., a script).

The session data structure 1110 may include other session stateinformation 1118, which may help to maintain a session and/or toterminate a session. For example, the other session state informationmay include a session identifier, which may be used by the client and/orserver to reference the session; a start date-time stamp for thesession; and/or session timeout data (e.g., a timestamp of the lastcommunication received from the client device and/or a maximum durationbetween communications for an active session).

In some implementations, the session data structure 1110 is stored inmemory (e.g., the memory 206) on an application server (e.g., the serverdevice 302). In some implementations, the session data structure 1110 isstored on a database server (e.g., the database server 116) and isaccessed via a network interface (e.g., the network communication unit218) by an application server (e.g., the server device 302) that isconducting the session with a client (e.g., the client device 312).

FIG. 11B is a memory map 1150 showing an example format for a datastructure 1160 associated with a session that is used to facilitate thedebugging, from a client device, of a set of instructions running on aserver. The data structure 1160 may be used to facilitate concurrencycontrol for an associated data structure (e.g., the session datastructure 1110). For example, the data structure 1160 may occur in or bereferenced by a pointer in a table of active sessions that also includesor references with a pointer a corresponding session data structure(e.g., the session data structure 1110) for the data structure 1160. Insome implementations, the data structure 1160 is associated with asession data structure by being part of a session data structure (e.g.,the session data structure 1110).

The data structure 1160 may include an access marker 1162 that may beused to help control access to a shared data structure (e.g., a sessiondata structure) by multiple threads and/or transactions. For example,the access marker 1162 may include a mutex. For example, the accessmarker 1162 may include a semaphore (e.g., a binary semaphore). In someimplementations, the access marker 1162 may include a transactionidentifier for identifying which transaction is currently using anassociated session data structure. In some implementations, the accessmarker 1162 may include a thread identifier for identifying which threadis currently using an associated session data structure.

The data structure 1160 may include a pause marker 1164 that may be usedto help limit the number of threads and/or transactions that may beconcurrently paused using an associated data structure (e.g., a sessiondata structure). In some implementations, the pause marker 1164 mayinclude a mutex or a binary semaphore and be used to prevent more thanone thread or transaction from being concurrently paused using a sessiondata structure (e.g., the session data structure 1110). In someimplementations, the pause marker 1164 may include a semaphore, and thenumber of concurrently paused threads or transactions may be limited toa larger number. In some implementations, the pause marker 1164 mayinclude a transaction identifier for identifying a transaction that ispaused using an associated session data structure. In someimplementations, the pause marker 1164 may include a thread identifierfor identifying a thread that is paused using an associated session datastructure.

In some implementations, the data structure 1160 is stored in memory(e.g., the memory 206) on an application server (e.g., the server device302). In some implementations, the data structure 1160 is stored on adatabase server (e.g., the database server 116) and is accessed via anetwork interface (e.g., the network communication unit 218) by anapplication server (e.g., the server device 302) that is conducting thesession with a client (e.g., the client device 312).

FIG. 12 is a state diagram 1200 of an example interface for debugging,from a client device, of a set of instructions running on a server. Thestate of a debugger instance determines what debugging actions areavailable and what information can be displayed. In someimplementations, an indication of the state of a debugger instance maybe presented to a user via a user interface (e.g., the user interface220), for example, as the debugger status 938 in the display region 910.

In the off state 1210, a debugger instance is inactive and does notpause scripts or display debugging information. In the waiting for firstbreakpoint state 1220, a debugger instance may initiate execution of aset of instructions (e.g., a script) and be ready to pause the scriptand display debugging information when it reaches a first breakpointassociated with the script. In the waiting for breakpoint state 1230, adebugger instance is searching for the next instruction or line of codeassociated with a breakpoint at which to pause. In the paused state1240, a debugger instance has paused at an instruction or a line ofcode, and the user can debug the script.

In some implementations, a transition 1250 from the off state 1210 tothe waiting for first breakpoint state 1220 occurs when a user starts ascript debugger instance by, for example, opening a debugger window ortab in a user interface (e.g., in the web browser 322) or starting adebugger instance with a hot key (e.g., pressing F2 to start a debuggerinstance).

In some implementations, a transition 1252 from the waiting for firstbreakpoint state 1220 to the paused state 1240 occurs when execution ofthe set of instructions (e.g., the script) first reaches an instructionof the set of instructions that is associated with a breakpoint andexecution is paused at that breakpoint.

Actions available in the paused state that do not cause a statetransition 1254 may include, for example, displaying the call stack;displaying transaction information; or displaying variable values.

In some implementations, a transition 1256 from the paused state 1240 tothe waiting for breakpoint state 1230 occurs when the user resumesprocessing by issuing a resume command, or when the user steps through ascript by issuing a step command (e.g., step into, step over, or stepout).

In some implementations, a transition 1258 from the waiting forbreakpoint state 1230 to the paused state 1240 occurs when execution ofthe set of instructions (e.g., a script) is paused at the nextbreakpoint, or when execution of the set of instructions (e.g., ascript) is paused at the next instruction (e.g., a script line)requiring evaluation following a step command (e.g., step into, stepover, or step out).

In some implementations, a transition 1260 from any other state to theoff state 1210 may occur when the user pauses execution of the set ofinstructions (e.g., a script); the user closes a debugger window or tabin the user interface (e.g., in the web browser 322); the user sessionends for any reason; or an administrator for the server (e.g., theserver device 302) resets all debugger instances running on the server(e.g., by navigating to a debugger_reset.do page).

FIG. 13 is a state diagram 1300 of an example session access controllerfor debugging, from a client device, of a set of instructions running ona server. In this example, use of a session is controlled using twobinary markers, a binary session access marker and a binary pausemarker. For example, the markers may be implemented as binarysemaphores. The session access marker may be locked when a transactionis currently using the session and unlocked otherwise. The pause markermay be locked when a transaction is currently paused using the sessionand unlocked otherwise.

In this example, there are five states. In state 1310, the access markeris unlocked and the pause marker is unlocked. The session is notreserved and is available for execution of transactions and to pausedebugged transactions. In state 1320, the access marker is locked andthe pause marker is unlocked. In this state, the session is being usedcurrently but no transaction is currently paused using the session. Instate 1330, the access marker is locked and the pause marker is locked,but by different transactions. For example, the pause marker and theaccess marker may respectively include a transaction identifier or otherinformation specifying which transaction has locked that marker. Thesession is being used currently by a transaction (e.g., a debug controltransaction) and another, different transaction (e.g., a debuggedtransaction) is currently paused using the session. In state 1332, theaccess marker is locked and the pause marker is locked by the sametransaction. The session is being used currently by a transaction thathas locked the pause marker (e.g., a debugged transaction). For example,state 1332 may be a transient state that is passed through as a systemimplements logic to update both the access marker and the pause markerat essentially the same time, although not actually simultaneously. Instate 1340, the access marker is unlocked and the pause marker islocked. The session is currently available for use but anothertransaction is currently paused using the session and thus pausing anadditional transaction using the session is not currently permitted.

State transition 1350 occurs when a transaction acquires the session byupdating the session access marker to the locked state. For, example thetransaction acquiring the session may be a debugged transaction (e.g.,with a set of instructions associated with one or more breakpoints), adebug control transaction (e.g., a resume or step command), or someother type of transaction that uses the session data structure (e.g., anunrelated request for a webpage from the server). The state transition1352 occurs when a transaction using the session completes and releasesthe session data structure by updating the session access marker to theunlocked state.

The state transition 1354 occurs when a debugged transaction reaches abreakpoint and pauses execution of its set of instructions. The statetransition 1354 changes the state from state 1320 to state 1340, via atransient stop at state 1332. The debugged transaction updates the pausemarker to the locked state to indicate that a transaction is pausedusing the data structure and then it releases the session by updatingthe session access marker to the unlocked state. The state transition1356 occurs when a debugged transaction resumes from a paused stateusing the session. The state transition 1356 changes the state fromstate 1340 to state 1320, via a transient stop at state 1332. Thedebugged transaction acquires the session by updating the session accessmarker to the locked state to indicate that a transaction is using thedata structure and then it updates the pause marker to the unlockedstate to indicate that a transaction is no longer paused using thesession.

State transition 1358 occurs when a transaction acquires the session byupdating the session access marker to the locked state while a differenttransaction (e.g., a debugged transaction) is paused. For, example thetransaction acquiring the session may be a debug control transaction(e.g., a resume or step command) or some other type of transaction thatuses the session data structure (e.g., an unrelated request for awebpage from the server). In state 1330, because the pause marker islocked, the currently executing transaction is not permitted to pauseexecution. In the case that a debugged transaction reaches a breakpointwhile the session is in state 1330, it will skip the breakpoint bycontinuing execution of its set of instructions without pausing at thebreakpoint. The state transition 1360 occurs when a transaction usingthe session completes and releases the session data structure byupdating the session access marker to the unlocked state.

The state diagram 1300 illustrates a five state example using a binarypause marker. In some implementations, not shown in FIG. 13, the pausemarker may be allowed to take on more than two values and the concurrentpausing of a limited number (greater than one) of debugged transactionsusing a session may be permitted. For example, debug controltransactions may be executed in a non-debug mode where breakpoints arenot checked or enforced or it may be assumed that debug controltransactions do not include breakpoints associated with theirinstructions that would cause them to pause. For example, where thepause marker is implemented as a counter that allows up to two pausedtransactions using a session, states similar to states 1330 and 1340 maybe entered when the maximum number of two paused debugged transactionsis reached.

FIG. 14 is a state diagram 1400 of an example session access controllerfor debugging, from a client device, of a set of instructions running ona server. In this example, use of a session is controlled using twobinary markers, a binary session access marker and a binary pausemarker. For example, the markers may be implemented as binarysemaphores. The session access marker may be locked when a transactionis currently using the session and unlocked otherwise. The example ofFIG. 14 differs from the example of FIG. 13 with regard to the handlingof the pause marker. In the example of FIG. 14, instead of unlocking thepause marker when a paused transaction resumes, the pause marker remainslocked by a debugged transaction until that debugged transaction isterminated. The pause marker may be locked when a transaction using thesession reaches a first breakpoint during its execution and the pausemarker may remain locked until that transaction completes execution oris otherwise terminated. This example handling of the pause marker mayprevent another debugged transaction from locking the pause marker whilethe first debugged transaction is executing between subsequentbreakpoints and ensure that the first debugged transaction is able tofinish debugging in the expected way once its first breakpoint has beenreached.

In this example, there are five states. In state 1410, the access markeris unlocked and the pause marker is unlocked. The session is notreserved and is available for execution of transactions and to pausedebugged transactions. In state 1420, the access marker is locked andthe pause marker is unlocked. In this state, the session is being usedcurrently but no transaction is currently paused using the session. Instate 1430, the access marker is locked and the pause marker is locked,but by different transactions. For example, the pause marker and theaccess marker may respectively include a transaction identifier or otherinformation specifying which transaction has locked that marker. Thesession is being used currently by a transaction (e.g., a debug controltransaction) and another, different transaction (e.g., a debuggedtransaction) has paused using the session and is holding the pausemarker. In state 1432, the access marker is locked and the pause markeris locked by the same transaction. The session is being used currentlyby a transaction that has locked the pause marker (e.g., a debuggedtransaction). In state 1440, the access marker is unlocked and the pausemarker is locked. The session is currently available for use but atransaction has paused using the session and is holding the pause markerand thus pausing an additional transaction using the session is notcurrently permitted.

State transition 1450 occurs when a transaction acquires the session byupdating the session access marker to the locked state. For, example thetransaction acquiring the session may be a debugged transaction (e.g.,with a set of instructions associated with one or more breakpoints), adebug control transaction (e.g., a resume or step command), or someother type of transaction that uses the session data structure (e.g., anunrelated request for a webpage from the server). The state transition1452 occurs when a transaction using the session completes and releasesthe session data structure by updating the session access marker to theunlocked state.

The state transition 1454 occurs when a debugged transaction reaches afirst breakpoint and pauses execution of its set of instructions. Thestate transition 1454 changes the state from state 1420 to state 1440,via a transient stop at state 1432. The debugged transaction updates thepause marker to the locked state to indicate that a transaction haspaused using the data structure and then it releases the session byupdating the session access marker to the unlocked state. In thisexample, the first breakpoint is special because it causes the pausemarker to be locked by the debugged transaction, which then continues tohold the pause marker lock until it is terminated.

The state transition 1456 occurs when a debugged transaction resumesfrom a paused state using the session. The debugged transaction acquiresthe session by updating the session access marker to the locked state toindicate that a transaction is using the data structure and continuesexecution of its set of instructions that are being debugged. The statetransition 1457 occurs when the debugged transaction holding the lock onthe pause marker pauses again, for example, at a subsequent breakpointafter the first breakpoint or after a step command. The debuggedtransaction, which is holding the lock on the pause marker, unlocks theaccess marker to allow other transaction (e.g., debug controltransactions) to run using the session while it is paused.

State transition 1458 occurs when a transaction acquires the session byupdating the session access marker to the locked state while a differenttransaction (e.g., a debugged transaction) is paused. For, example thetransaction acquiring the session may be a debug control transaction(e.g., a resume or step command) or some other type of transaction thatuses the session data structure (e.g., an unrelated request for awebpage from the server). In state 1430, because the pause marker islocked, the currently executing transaction is not permitted to pauseexecution. In the case that a debugged transaction reaches a breakpointwhile the session is in state 1430, it will skip the breakpoint bycontinuing execution of its set of instructions without pausing at thebreakpoint. The state transition 1460 occurs when a transaction usingthe session completes and releases the session data structure byupdating the session access marker to the unlocked state.

The state transition 1462 occurs when a debugged transaction that holdsthe lock on the pause marker is terminated (e.g., upon completingexecution of its set of instructions). The state transition 1462 changesthe state from state 1432 to state 1410, via a transient stop at state1420. The debugged transaction updates the pause marker to the unlockedstate and then it releases the session by updating the session accessmarker to the unlocked state.

The state diagram 1400 illustrates a five state example using a binarypause marker. In some implementations, not shown in FIG. 14, the pausemarker may be allowed to take on more than two values and the concurrentpausing of a limited number (greater than one) of debugged transactionsusing a session may be permitted. For example, debug controltransactions may be executed in a non-debug mode where breakpoints arenot checked or enforced or it may be assumed that debug controltransactions do not include breakpoints associated with theirinstructions that would cause them to pause. For example, where thepause marker is implemented as a counter that allows up to two pausedtransactions using a session, states similar to states 1430 and 1440 maybe entered when the maximum number of two paused debugged transactionsis reached.

In some implementations, a user may disable a debugger instance (e.g.,by selecting the disable debugging icon in the command icons 950) inorder to continue executing a paused set of instructions (e.g., ascript) in a non-debug mode (e.g., a production mode) where it skipsremaining breakpoints and consumes less computing resources on a server(e.g., the server device 302).

In some implementations, a user can launch a server-side debuggerinstance from an application navigator, Studio, or from a syntax editor.In some implementations, a debugger transaction remains open as long asan associated user session is valid. If a user session logs out or timesout, the system may terminate the debugger transaction.

In some implementations, an administrator for a server (e.g., the serverdevice 302) may grant permission to launch debugger instances on theserver to individual users. In some implementations, an administratorfor a server (e.g., the server device 302) may configure a limit (e.g.,a quarter of the number of semaphores in the application node or thenumber of semaphores in the node minus two) on the number of concurrentdebugger instances that can run on an application node (e.g., theapplication module 330). In some implementations, an administrator for aserver (e.g., the server device 302) may reset, turn off, or disablescript debugging for the entire server.

In some implementations, breakpoints for scripts on a server (e.g., theserver device 302) are stored or referenced in a breakpoint table. Forexample, a breakpoint table may be associated with an individual user,and many users can have their own table of breakpoints. For example,different users may be able to debug the same script with differentbreakpoints. In some implementations, breakpoints may be set or removedin a regular code editor or in a debugger interface (e.g., in the codingpane 920 of the display region 910).

Some implementations of a debugger interface may use a representationalstate transfer (REST) API.

All or a portion of the implementations of the systems and techniquesdescribed herein can be implemented using a general-purposecomputer/processor with a computer program that, when executed, carriesout any of the respective techniques, algorithms, or machine-readablecode described herein. In addition, or alternatively, for example, aspecial-purpose computer/processor can be utilized, which can includespecialized hardware for carrying out any of the techniques, algorithms,or machine-readable code described herein.

The implementations of computing devices as described herein (and thealgorithms, techniques, machine-readable code, etc., stored thereon orexecuted thereby) can be realized in hardware, software, or acombination thereof. The hardware can include, for example, computers,intellectual property (IP) cores, application-specific integratedcircuits (ASICs), programmable logic arrays, optical processors,programmable logic controllers, microcode, microcontrollers, servers,microprocessors, digital signal processors, or any other suitablecircuit. In the claims, the term “processor” should be understood asencompassing any of the foregoing hardware, either singly or incombination.

For example, one or more computing devices can include an ASIC orprogrammable logic array (e.g., a field-programmable gate array (FPGA))configured as a special-purpose processor to perform one or more of theoperations described or claimed herein. An example FPGA can include acollection of logic blocks and random access memory (RAM) blocks thatcan be individually configured or configurably interconnected in orderto cause the FPGA to perform certain functions. Certain FPGAs cancontain other general- or special-purpose blocks as well. An exampleFPGA can be programmed based on a hardware definition language (HDL)design, such as VHSIC Hardware Description Language or Verilog.

The implementations disclosed herein can be described in terms offunctional block components and various processing operations. Suchfunctional block components can be realized by any number of hardware orsoftware components that perform the specified functions. For example,the described implementations can employ various integrated circuitcomponents (e.g., memory elements, processing elements, logic elements,look-up tables, and the like), which can carry out a variety offunctions under the control of one or more microprocessors or othercontrol devices. Similarly, where the elements of the describedimplementations are implemented using software programming or softwareelements, the systems and techniques can be implemented with anyprogramming or scripting language, such as C, C++, Java, assembler, orthe like, with the various algorithms being implemented with acombination of data structures, objects, processes, routines, or otherprogramming elements. Functional aspects can be implemented inalgorithms that execute on one or more processors. Furthermore, theimplementations of the systems and techniques could employ any number ofconventional techniques for electronics configuration, signal processingor control, data processing, and the like. The words “mechanism” and“element” are used broadly and are not limited to mechanical or physicalimplementations, but can include software routines in conjunction withprocessors, etc.

Likewise, the terms “module” or “monitor” as used herein and in thefigures may be understood as corresponding to a functional unitimplemented using software, hardware (e.g., an ASIC), or a combinationof software and hardware. In certain contexts, such modules or monitorsmay be understood to be a processor-implemented software module orsoftware-implemented monitor that is part of or callable by anexecutable program, which may itself be wholly or partly composed ofsuch linked modules or monitors.

Implementations or portions of implementations of the above disclosurecan take the form of a computer program product accessible from, forexample, a computer-usable or computer-readable medium. Acomputer-usable or computer-readable medium can be any device that can,for example, tangibly contain, store, communicate, or transport aprogram or data structure for use by or in connection with anyprocessor. The medium can be, for example, an electronic, magnetic,optical, electromagnetic, or semiconductor device. Other suitablemediums are also available. Such computer-usable or computer-readablemedia can be referred to as non-transitory memory or media, and caninclude RAM or other volatile memory or storage devices that can changeover time. A memory of an apparatus described herein, unless otherwisespecified, does not have to be physically contained by the apparatus,but is one that can be accessed remotely by the apparatus, and does nothave to be contiguous with other memory that might be physicallycontained by the apparatus.

The word “example” is used herein to mean serving as an example,instance, or illustration. Any aspect or design described herein as“example” is not necessarily to be construed as preferred oradvantageous over other aspects or designs. Rather, the use of the word“example” is intended to present concepts in a concrete fashion. The useof any and all examples, or language suggesting that an example is beingdescribed (e.g., “such as”), provided herein is intended merely tobetter illuminate the systems and techniques and does not pose alimitation on the scope of the systems and techniques unless otherwiseclaimed. As used in this application, the term “or” is intended to meanan inclusive “or” rather than an exclusive “or.” That is, unlessspecified otherwise or clearly indicated otherwise by the context, thestatement “X includes A or B” is intended to mean any of the naturalinclusive permutations thereof. For example, if X includes A; X includesB; or X includes both A and B, then “X includes A or B” is satisfiedunder any of the foregoing instances. In addition, the articles “a” and“an” as used in this application and the appended claims shouldgenerally be construed to mean “one or more,” unless specified otherwiseor clearly indicated by the context to be directed to a singular form.Moreover, the use of the term “an implementation” or the term “oneimplementation” throughout this disclosure is not intended to mean thesame implementation unless described as such.

The particular implementations shown and described herein areillustrative examples of the systems and techniques and are not intendedto otherwise limit the scope of the systems and techniques in any way.For the sake of brevity, conventional electronics, control systems,software development, and other functional aspects of the systems (andcomponents of the individual operating components of the systems) cannotbe described in detail. Furthermore, the connecting lines, orconnectors, shown in the various figures presented are intended torepresent example functional relationships or physical or logicalcouplings between the various elements. Many alternative or additionalfunctional relationships, physical connections, or logical connectionscan be present in a practical device. Moreover, no item or component isessential to the practice of the systems and techniques unless theelement is specifically described as “essential” or “critical.”

The use of the terms “including,” “comprising,” “having,” or variationsthereof herein is meant to encompass the items listed thereafter andequivalents thereof as well as additional items. Unless specified orlimited otherwise, the terms “mounted,” “connected,” “supported,”“coupled,” or variations thereof are used broadly and encompass bothdirect and indirect mountings, connections, supports, and couplings.Further, “connected” and “coupled” are not restricted to physical ormechanical connections or couplings.

Unless otherwise indicated herein, the recitation of ranges of valuesherein is intended merely to serve as a shorthand alternative toreferring individually to respective separate values falling within therange, and respective separate values are incorporated into thespecification as if individually recited herein. Finally, the operationsof all techniques described herein are performable in any suitable orderunless clearly indicated otherwise by the context.

All references, including publications, patent applications, andpatents, cited herein are hereby incorporated by reference to the sameextent as if each respective reference were individually andspecifically indicated as being incorporated by reference and were setforth in its entirety herein.

The above-described implementations have been described in order tofacilitate easy understanding of the present systems and techniques, andsuch descriptions of such implementations do not limit the presentsystems and techniques. To the contrary, the present systems andtechniques are intended to cover various modifications and equivalentarrangements included within the scope of the appended claims, whichscope is to be accorded the broadest interpretation as is permitted bylaw so as to encompass all such modifications and equivalentarrangements.

The techniques presented and claimed herein are referenced and appliedto material objects and concrete examples of a practical nature thatdemonstrably improve the present technical field and, as such, are notabstract, intangible or purely theoretical. Further, if any claimsappended to the end of this specification contain one or more elementsdesignated as “means for [perform]ing [a function] . . . ” or “step for[perform]ing [a function] . . . ”, it is intended that such elements areto be interpreted under 35 U.S.C. 112(f). However, for any claimscontaining elements designated in any other manner, it is intended thatsuch elements are not to be interpreted under 35 U.S.C. 112(f).

What is claimed is:
 1. A system for providing a client-side debuggerinterface for a server-executed set of instructions, the systemcomprising: a memory; a processor; and a network interface, wherein thememory includes machine-readable code executable by the processor to:receive a first request from a client device; responsive to receivingthe first request, identify a first set of instructions to be executed,wherein the first set of instructions is associated with at least onebreakpoint; initiate execution of the first set of instructions;determine, based on a marker, that pausing execution using a sessiondata structure is permitted; pause execution of the first set ofinstructions when an instruction of the first set of instructionsassociated with a first breakpoint is reached; after the firstbreakpoint is reached and before a new request is received from theclient device, transmit, to the client device, a message that indicatesthat a breakpoint has been reached; and terminate execution of the firstset of instructions responsive to determining that a debugger interfaceon the client device is no longer available to control execution of thefirst set of instructions.
 2. The system of claim 1, wherein themachine-readable code to terminate execution of the first set ofinstructions comprises machine-readable code to: terminate debugging ofthe first set of instructions by a script interpreter by sending acommand to a debug interface of a script interpreter to stopinterpreting or debugging the first set of instructions.
 3. The systemof claim 1, wherein the message that indicates that a breakpoint hasbeen reached is transmitted via a WebSocket.
 4. The system of claim 1,wherein the message that indicates that a breakpoint has been reached istransmitted via a channel established by long polling from the clientdevice.
 5. The system of claim 1, wherein the memory includesmachine-readable code executable by the processor to: determine that asession associated with the first request has terminated; and responsiveto the determination that the session associated with the first requesthas terminated, skip one or more remaining breakpoints associated withthe first set of instructions.
 6. The system of claim 1, wherein thememory includes machine-readable code executable by the processor to:determine that execution of the first set of instructions will becontinued from a paused state; and responsive to the determination thatexecution of the first set of instructions will be continued from apaused state, update the marker to indicate that execution of the firstset of instructions is no longer paused using the session datastructure.
 7. The system of claim 1, wherein the first set ofinstructions is a script and execution of the first set of instructionsincludes interpreting instructions of the first set of instructionsusing a script interpreter executed by the processor.
 8. The system ofclaim 7, wherein the script interpreter includes a debug interface thatpermits an application executed by the processor to pause and continueexecution of the first set of instructions by interfacing with the debuginterface.
 9. A method for providing a client-side debugger interfacefor a server-executed set of instructions, the method comprising:identifying a first set of instructions to be executed, wherein thefirst set of instructions is associated with at least one breakpoint;initiating execution of the first set of instructions; pausing executionof the first set of instructions when an instruction of the first set ofinstructions associated with a first breakpoint is reached; after thefirst breakpoint is reached and before a new request is received from aclient device, transmitting, to the client device, a message thatindicates that a breakpoint has been reached; determining that a user isnot permitted to access an instruction of the first set of instructionsthat is associated with a second breakpoint; responsive to thedetermination that the user is not permitted to access the instructionfrom the first set of instructions that is associated with the secondbreakpoint, skipping the second breakpoint by executing the instructionof the first set of instructions associated with the second breakpointwithout pausing execution of the first set of instructions; andterminating execution of the first set of instructions responsive todetermining that a debugger interface on the client device is no longeravailable to control execution of the first set of instructions.
 10. Themethod of claim 9, wherein terminating execution of the first set ofinstructions comprises: terminating debugging of the first set ofinstructions by a script interpreter by sending a command to a debuginterface of a script interpreter to stop interpreting or debugging thefirst set of instructions.
 11. The method of claim 9, wherein themessage that indicates that a breakpoint has been reached is transmittedvia a WebSocket.
 12. The method of claim 9, wherein the message thatindicates that a breakpoint has been reached is transmitted via achannel established by long polling from the client device.
 13. Themethod of claim 9, comprising: determining that a session hasterminated; and skipping a second breakpoint by executing an instructionof the first set of instructions associated with the second breakpointwithout pausing execution of the first set of instructions.
 14. Anon-transitory computer-readable storage medium, comprising executableinstructions that, when executed by a processor, facilitate performanceof operations, comprising: receiving a first request from a clientdevice; responsive to receiving the first request, identifying a firstset of instructions to be executed, wherein the first set ofinstructions is associated with at least one breakpoint; initiatingexecution of the first set of instructions; determining, based on amarker, that pausing execution using a session data structure ispermitted; pausing execution of the first set of instructions when aninstruction of the first set of instructions associated with a firstbreakpoint is reached; after the first breakpoint is reached and beforea new request is received from the client device, transmitting, to theclient device, a message that indicates that a breakpoint has beenreached; and terminating execution of the first set of instructionsresponsive to determining that a debugger interface on the client deviceis no longer available to control execution of the first set ofinstructions.
 15. A system for providing a client-side debuggerinterface for a server-executed set of instructions, the systemcomprising: a memory; a processor; and a network interface, wherein thememory includes machine-readable code executable by the processor to:receive a first request from a client device; responsive to receivingthe first request, identify a first set of instructions to be executed,wherein the first set of instructions is associated with at least onebreakpoint; initiate execution of the first set of instructions; pauseexecution of the first set of instructions when an instruction of thefirst set of instructions associated with a first breakpoint is reached;after the first breakpoint is reached and before a new request isreceived from the client device, transmit, to the client device, amessage that indicates that a breakpoint has been reached; and terminateexecution of the first set of instructions responsive to determiningthat a debugger interface on the client device is no longer available tocontrol execution of the first set of instructions, wherein the memoryincludes machine-readable code executable by the processor to: determinethat a user is not permitted to access an instruction of the first setof instructions that is associated with a second breakpoint; andresponsive to the determination that the user is not permitted to accessthe instruction from the first set of instructions that is associatedwith the second breakpoint, skip the second breakpoint by executing theinstruction of the first set of instructions associated with the secondbreakpoint without pausing execution of the first set of instructions.16. A system for providing a client-side debugger interface for aserver-executed set of instructions, the system comprising: a memory; aprocessor; and a network interface, wherein the memory includesmachine-readable code executable by the processor to: receive a firstrequest from a client device; responsive to receiving the first request,identify a first set of instructions to be executed, wherein the firstset of instructions is associated with at least one breakpoint; initiateexecution of the first set of instructions; pause execution of the firstset of instructions when an instruction of the first set of instructionsassociated with a first breakpoint is reached; after the firstbreakpoint is reached and before a new request is received from theclient device, transmit, to the client device, a message that indicatesthat a breakpoint has been reached; and terminate execution of the firstset of instructions responsive to determining that a debugger interfaceon the client device is no longer available to control execution of thefirst set of instructions, wherein the memory includes machine-readablecode executable by the processor to: receive a second request from theclient device to step into a second set of instructions from the firstset of instructions; determine that a user is not permitted to accessthe second set of instructions; and responsive to the determination thatthe user is not permitted to access the second set of instructions, stepover the second set of instructions by executing the second set ofinstructions without pausing execution of the first set of instructions.17. A system for providing a client-side debugger interface for aserver-executed set of instructions, the system comprising: a memory; aprocessor; and a network interface, wherein the memory includesmachine-readable code executable by the processor to: receive a firstrequest from a client device; responsive to receiving the first request,identify a first set of instructions to be executed, wherein the firstset of instructions is associated with at least one breakpoint; initiateexecution of the first set of instructions; pause execution of the firstset of instructions when an instruction of the first set of instructionsassociated with a first breakpoint is reached; after the firstbreakpoint is reached and before a new request is received from theclient device, transmit, to the client device, a message that indicatesthat a breakpoint has been reached; and terminate execution of the firstset of instructions responsive to determining that a debugger interfaceon the client device is no longer available to control execution of thefirst set of instructions, wherein the memory includes machine-readablecode executable by the processor to, as a precondition for pausing atthe first breakpoint, determine, based on a marker, that a number ofconcurrently paused transactions using a session data structure has notexceeded a limit.
 18. A method for providing a client-side debuggerinterface for a server-executed set of instructions, the methodcomprising: identifying a first set of instructions to be executed,wherein the first set of instructions is associated with at least onebreakpoint; initiating execution of the first set of instructions;pausing execution of the first set of instructions when an instructionof the first set of instructions associated with a first breakpoint isreached; after the first breakpoint is reached and before a new requestis received from a client device, transmitting, to the client device, amessage that indicates that a breakpoint has been reached; receiving arequest from the client device to step into a second set of instructionsfrom the first set of instructions; determining that a user is notpermitted to access the second set of instructions; and responsive tothe determination that the user is not permitted to access the secondset of instructions, stepping over the second set of instructions byexecuting the second set of instructions without pausing execution ofthe first set of instructions; and terminating execution of the firstset of instructions responsive to determining that a debugger interfaceon the client device is no longer available to control execution of thefirst set of instructions.